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Tandon SS, Bunge SD, Patel N, Wang EC, Thompson LK. Self-Assembly of Antiferromagnetically-Coupled Copper(II) Supramolecular Architectures with Diverse Structural Complexities. Molecules 2020; 25:molecules25235549. [PMID: 33256163 PMCID: PMC7734591 DOI: 10.3390/molecules25235549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 11/16/2022] Open
Abstract
The self-assembly of 2,6-diformyl-4-methylphenol (DFMP) and 1-amino-2-propanol (AP)/2-amino-1,3-propanediol (APD) in the presence of copper(II) ions results in the formation of six new supramolecular architectures containing two versatile double Schiff base ligands (H3L and H5L1) with one-, two-, or three-dimensional structures involving diverse nuclearities: tetranuclear [Cu4(HL2−)2(N3)4]·4CH3OH·56H2O (1) and [Cu4(L3−)2(OH)2(H2O)2] (2), dinuclear [Cu2(H3L12−)(N3)(H2O)(NO3)] (3), polynuclear {[Cu2(H3L12−)(H2O)(BF4)(N3)]·H2O}n (4), heptanuclear [Cu7(H3L12−)2(O)2(C6H5CO2)6]·6CH3OH·44H2O (5), and decanuclear [Cu10(H3L12−)4(O)2(OH)2(C6H5CO2)4] (C6H5CO2)2·20H2O (6). X-ray studies have revealed that the basic building block in 1, 3, and 4 is comprised of two copper centers bridged through one μ-phenolate oxygen atom from HL2− or H3L12−, and one μ-1,1-azido (N3−) ion and in 2, 5, and 6 by μ-phenoxide oxygen of L3− or H3L12− and μ-O2− or μ3-O2− ions. H-bonding involving coordinated/uncoordinated hydroxy groups of the ligands generates fascinating supramolecular architectures with 1D-single chains (1 and 6), 2D-sheets (3), and 3D-structures (4). In 5, benzoate ions display four different coordination modes, which, in our opinion, is unprecedented and constitutes a new discovery. In 1, 3, and 5, Cu(II) ions in [Cu2] units are antiferromagnetically coupled, with J ranging from −177 to −278 cm−1.
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Affiliation(s)
- Santokh S. Tandon
- Department of Chemistry and Biochemistry, Kent State University-Salem Campus, Salem, OH 44460, USA
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA; (S.D.B.); (N.P.); (E.C.W.)
- Correspondence: ; Tel.: +1-330-337-4235
| | - Scott D. Bunge
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA; (S.D.B.); (N.P.); (E.C.W.)
| | - Neil Patel
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA; (S.D.B.); (N.P.); (E.C.W.)
| | - Esther C. Wang
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA; (S.D.B.); (N.P.); (E.C.W.)
| | - Laurence K. Thompson
- Department of Chemistry, Memorial University, St. John’s Newfoundland, NL A1B 3X7, Canada;
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Tandon SS, Bunge SD, Toth SA, Sanchiz J, Thompson LK, Shelley JT. Antiferromagnetically Coupled Dimeric Dodecacopper Supramolecular Architectures of Macrocyclic Ligands with a Symmetrical μ6-BO3(3-) Central Moiety. Inorg Chem 2015; 54:6873-84. [PMID: 26113440 DOI: 10.1021/acs.inorgchem.5b00771] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions between 2,6-diformyl-4-alkyl(R)-phenol (R = CH3 or C(CH3)3) and 1,3-diamino-2-hydroxypropane (1,3-DAP) in the presence of copper(II) salts (Cu(BF4)2·6H2O, Cu(ClO4)2·6H2O/H3BO3/Ar) and triethylamine (TEA) in a single pot result in self-assembly of dimeric dodecacopper supramolecular architectures of 30-membered hexatopic macrocyclic ligands (H6L4 and H6L5) with unique and fascinating structures having the BO3(3-) anion as the central species bonded to all six copper centers in a symmetrical fashion (μ6-BO3(3-)). A number of closely related macrocyclic hexacopper complexes are reported: {[Cu6(L4)(μ6-BO3)(μ-H2O)(C3H7NO)2(BF4)][BF4]2·3C3H7NO}2 (1) (DMF = C3H7NO), {[Cu6(L4)(μ6-BO3)(μ-C3H7NO)3][ClO4]3·3C3H7NO}2 (2), {[Cu6(L5)(μ6-BO3)(μ-OH)(H2O)3(C3H7NO)][BF4]2·6C3H7NO·4C2H5OH·2H2O}2 (3), {[Cu6(L5)(μ6-BO3)(μ-CH3OH)(CH3OH)2][ClO4]3·10H2O}2 (4), and {[Cu6(L5)(μ6-BO3)(μ-CH3CO2)(μ-CH3O)(CH3OH)][BF4]·13CH3OH·8H2O}2 (5). A polymeric side product {[Cu2(H2L2)(CH3OH)(BF4)][BF4]}n (6), involving a 2 + 2 macrocyclic ligand, was also isolated and structurally characterized. Complex 6 involves dinuclear copper(II) units linked through BF4(-) anions to form a novel 1D single-chain polymeric coordination compound. This appears to be the first report in which a central BO3(3-) species is linked to six copper(II) ions held together by a single macrocyclic ligand through three μ1,1-O(BO3(3-)) and three μ1,3-O(BO3(3-)) bridges. In complexes 1-5 the BO3(3-) is present in the center of the macrocyclic cavity and is bonded to all six metal centers arranged in a benzene-like hexagonal array. In the hexagonal array there are alternate double (μ-alkoxide and μ1,3-O(BO3(3-))) and (μ-phenoxide and μ1,1-O(BO3(3-))) bridges between the Cu(II) centers. The symmetrical hexa-bridging nature of μ6-BO3(3-) is unprecedented in transition metal complex chemistry, and along with alkoxide and phenoxide bridges in the equatorial plane provides effective pathways for an overall antiferromagnetic exchange interaction between six copper(II) centers. In 1, 3, and 5 the BO3(3-) moiety is produced in one step (synthetic) by an unusual copper(II)-macrocycle complex catalyzed hydrolysis of BF4(-) ion in methanol. In 2 and 4 the central species (BO3(3-)) comes from boric acid (H3BO3) which is added to reaction mixture of Cu(ClO4)2/H6L4/H6L5 under inert conditions to confirm the identity of the central species.
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Affiliation(s)
- Santokh S Tandon
- †Department of Chemistry, Kent State University Salem, 2491 State Route 45 South, Salem, Ohio 44460, United States.,‡Department of Chemistry, Kent State University, 1175 Risman Drive, Kent, Ohio 44242, United States
| | - Scott D Bunge
- ‡Department of Chemistry, Kent State University, 1175 Risman Drive, Kent, Ohio 44242, United States
| | - Sara A Toth
- ‡Department of Chemistry, Kent State University, 1175 Risman Drive, Kent, Ohio 44242, United States
| | - Joaquin Sanchiz
- §Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, 38206 Tenerife, Spain
| | - Laurence K Thompson
- ∥Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada
| | - Jacob T Shelley
- ‡Department of Chemistry, Kent State University, 1175 Risman Drive, Kent, Ohio 44242, United States
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Anwar MU, Dawe LN, Parsons SR, Tandon SS, Thompson LK, Dey SK, Mereacre V, Reiff WM, Bunge SD. Oligonuclear Fe Complexes (Fe, Fe4, Fe6, Fe9) Derived from Tritopic Pyridine Bis-Hydrazone Ligands—Structural, Magnetic, and Mössbauer Studies. Inorg Chem 2014; 53:4655-68. [DOI: 10.1021/ic500348k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Muhammad U. Anwar
- Department of Chemistry, Memorial University, St. John’s, Newfoundland A1B3X7, Canada
| | - Louise N. Dawe
- Department of Chemistry, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada
| | - Stewart R. Parsons
- Department of Chemistry, Memorial University, St. John’s, Newfoundland A1B3X7, Canada
| | - Santokh S. Tandon
- Department of Chemistry, Kent State University—Salem, Salem, Ohio 44460, United States
| | - Laurence K. Thompson
- Department of Chemistry, Memorial University, St. John’s, Newfoundland A1B3X7, Canada
| | - Subrata K. Dey
- Department of Chemistry, Memorial University, St. John’s, Newfoundland A1B3X7, Canada
| | - Valeriu Mereacre
- Department of Chemistry, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - William M. Reiff
- Department of Chemistry, Northeastern University, Boston, Massachusetts 02115, United States
| | - Scott D. Bunge
- Department of
Chemistry, Kent State University, Kent, Ohio 44242, United States
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Anwar MU, Dawe LN, Tandon SS, Bunge SD, Thompson LK. Polynuclear lanthanide (Ln) complexes of a tri-functional hydrazone ligand – mononuclear (Dy), dinuclear (Yb, Tm), tetranuclear (Gd), and hexanuclear (Gd, Dy, Tb) examples. Dalton Trans 2013; 42:7781-94. [DOI: 10.1039/c3dt32732a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tandon SS, Bunge SD, Sanchiz J, Thompson LK. Structures and magnetic properties of an antiferromagnetically coupled polymeric copper(II) complex and ferromagnetically coupled hexanuclear nickel(II) clusters. Inorg Chem 2012; 51:3270-82. [PMID: 22339539 DOI: 10.1021/ic202732k] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reactions between 2,6-diformyl-4-methylphenol (DFMF) and tris(hydroxymethyl) aminomethane (THMAM = H(3)L2) in the presence of copper(II) salts, CuX(2) (X = CH(3)CO(2)(-), BF(4)(-), ClO(4)(-), Cl(-), NO(3)(-)) and Ni(CH(3)CO(2))(2) or Ni(ClO(4))(2)/NaC(6)H(5)CO(2), sodium azide (NaN(3)), and triethylamine (TEA), in one pot self-assemble giving a coordination polymer consisting of repeating pentanuclear copper(II) clusters {[Cu(2)(H(5)L(2-))(μ-N(3))](2)[Cu(N(3))(4)]·2CH(3)OH}(n) (1) and hexanuclear Ni(II) complexes [Ni(6)(H(3)L1(-))(2)(HL2(2-))(2)(μ-N(3))(4)(CH(3)CO(2))(2)]·6C(3)H(7)NO·C(2)H(5)OH (2) and [Ni(6)(H(3)L1(-))(2)(HL2(2-))(2)(μ-N(3))(4)(C(6)H(5)CO(2))(2)]·3C(3)H(7)NO·3H(2)O·CH(3)OH (3). In 1, H(5)L(2-) and in 2 and 3 H(3)L1(-) and HL2(2-) represent doubly deprotonated, singly deprotonated, and doubly deprotonated Schiff-base ligands H(7)L and H(4)L1 and a tripodal ligand H(3)L2, respectively. 1 has a novel double-stranded ladder-like structure in which [Cu(N(3))(4)](2-) anions link single chains comprised of dinuclear cationic subunits [Cu(2)(H(5)L(2-))(μ-N(3))](+), forming a 3D structure of interconnected ladders through H bonding. Nickel(II) clusters 2 and 3 have very similar neutral hexanuclear cores in which six nickel(II) ions are bonded to two H(4)L1, two H(3)L2, four μ-azido, and two μ-CH(3)CO(2)(-)/μ-C(6)H(5)CO(2)(-) ligands. In each structure two terminal dinickel (Ni(2)) units are connected to the central dinickel unit through four doubly bridging end-on (EO) μ-azido and four triply bridging μ(3)-methoxy bridges organizing into hexanuclear units. In each terminal dinuclear unit two nickel centers are bridged through one μ-phenolate oxygen from H(3)L1(-), one μ(3)-methoxy oxygen from HL2(2-), and one μ-CH(3)CO(2)(-) (2)/μ-C(6)H(5)CO(2)(-) (3) ion. Bulk magnetization measurements on 1 show moderately strong antiferromagnetic coupling within the [Cu(2)] building block (J(1) = -113.5 cm(-1)). Bulk magnetization measurements on 2 and 3 demonstrate that the magnetic interactions are completely dominated by ferromagnetic coupling occurring between Ni(II) ions for all bridges with coupling constants (J(1), J(2), and J(3)) ranging from 2.10 to 14.56 cm(-1) (in the Ĥ = -J(1)(Ŝ(1)Ŝ(2)) - J(1)(Ŝ(2)Ŝ(3)) - J(2)(Ŝ(3)Ŝ(4)) - J(1)(Ŝ(4)Ŝ(5)) - J(1)(Ŝ(5)Ŝ(6)) - J(2)(Ŝ(1)Ŝ(6)) - J(3)(Ŝ(2)Ŝ(6)) - J(3)(Ŝ(2)Ŝ(5)) - J(3)(Ŝ(3)Ŝ(5)) convention).
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Affiliation(s)
- Santokh S Tandon
- Department of Chemistry, Kent State University-Salem, Salem, Ohio 44460, USA.
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Anwar MU, Tandon SS, Dawe LN, Habib F, Murugesu M, Thompson LK. Lanthanide Complexes of Tritopic Bis(hydrazone) Ligands: Single-Molecule Magnet Behavior in a Linear DyIII3 Complex. Inorg Chem 2011; 51:1028-34. [DOI: 10.1021/ic2022006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Muhammad U. Anwar
- Department of Chemistry, Memorial University, St. John’s,
Newfoundland A1B 3X7, Canada
| | - Santokh S. Tandon
- Department of Chemistry, Kent State University at Salem, Salem,
Ohio 44460, United States
| | - Louise N. Dawe
- Department of Chemistry, Memorial University, St. John’s,
Newfoundland A1B 3X7, Canada
| | - Fatemah Habib
- Department of Chemistry, University of Ottawa, 10 Marie Curie,
Ottawa, Ontario K1N 6N5, Canada
| | - Muralee Murugesu
- Department of Chemistry, University of Ottawa, 10 Marie Curie,
Ottawa, Ontario K1N 6N5, Canada
| | - Laurence K. Thompson
- Department of Chemistry, Memorial University, St. John’s,
Newfoundland A1B 3X7, Canada
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Tandon SS, Dul MC, Lee JL, Dawe LN, Anwar MU, Thompson LK. Complexes of ditopic carbo- and thio-carbohydrazone ligands--mononuclear, 1D chain, dinuclear and tetranuclear examples. Dalton Trans 2011; 40:3466-75. [PMID: 21347464 DOI: 10.1039/c0dt01487g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ligands based on carbo- and thio-carbohydrazone cores, modified with pyridine, carboxylate and oxime ends, have been examined. They display a tautomeric versatility based on the flexible nature of the hydrazone linkages, leading to varied coordination motifs. Examples of mononuclear (Co(II), Ni(II)), dinuclear (Co(III)), 1D chain (Cu(II)) and square [2 × 2] grid (Ni(II)) complexes are obtained. Ferromagnetic (Cu(II)) and antiferromagnetic (Ni(II)) exchange is observed, with spin coupling in the Ni(II)(4) square grids propagated through the μ-O and μ-S bridges. Weak antiferromagnetic exchange (J = -6.0 cm(-1)) is observed for the μ-O bridged grid, despite the large Ni-O-Ni angles (137-141°), while for the μ-S bridged grids much stronger exchange is observed (J = -148 cm(-1), -198 cm(-1)). This is much larger than expected based on the Ni-S-Ni bridge angles (151-169°), and is associated with the soft (less polarizing than oxygen) nature of the sulfur bridge, which would allow for much more efficient transmission of spin exchange than observed in the μ-O bridged case. Structures and variable temperature magnetic data are included, and spin exchange is analyzed using normal Heisenberg exchange models. No examples involving oxime (NO) bridging are reported, which reflects the positioning of the N,O and N,S donor combinations in each ligand, and the preferred coordination through these donor atoms.
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Affiliation(s)
- Santokh S Tandon
- Department of Chemistry, Kent State University at Salem, Salem, OH 44460, USA
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Shuvaev KV, Tandon SS, Dawe LN, Thompson LK. Unexpected Ni(ii) and Cu(ii) polynuclear assemblies—a balance between ligand and metal ion coordination preferences. Chem Commun (Camb) 2010; 46:4755-7. [DOI: 10.1039/c0cc00150c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tandon SS, Bunge SD, Patel N, Thompson LK. The synthesis, structure, and magnetic properties of a novel copper(II) cluster with H-bonding directed 3D-structure comprised of interconnected double-stranded ladders. INORG CHEM COMMUN 2009. [DOI: 10.1016/j.inoche.2009.08.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tandon SS, Bunge SD, Rakosi R, Xu Z, Thompson LK. Self-assembly of mixed-valence Co(ii/iii) and Ni(ii) clusters: azide-bridged 1D single chain coordination polymers comprised of tetranuclear units, tetranuclear Co(ii/iii) complexes, ferromagnetically coupled azide-bridged tetranuclear, and hexanuclear Ni(ii) complexes: synthesis, structural, and magnetic properties. Dalton Trans 2009:6536-51. [DOI: 10.1039/b903617b] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tandon SS, Lucas CR. Metal-induced facile synthesis of a tricyclic system — 10-Methyl-12-thia-2,9-diaza-tricyclo[8.3.1.03,8]tetradeca-3,5,7-triene-1-carbonitrile. Formation of an intramolecular carbon–carbon bond. CAN J CHEM 2008. [DOI: 10.1139/v08-100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The reaction between 4-thiaheptane-2,6-dione and 1,2-diaminobenzene in the presence of nickel(II) perchlorate results in the formation of a nickel(II) complex of a novel new heterotricyclic system: 1-methoxy-10-methyl-12-thia-2,9-diaza-tricyclo[8.3.1.03,8]tetradeca-3,5,7-triene, which on treatment with potassium cyanide gives 10-methy-12-thia-2,9-diaza-tricyclo[8.3.1.03,8]tetradeca-3,5,7-triene-1-carbonitrile, a case of metal-induced carbon–carbon bond formation.Key words: nickel-induced carbon–carbon bond formation, intramolecular cyclization, tricyclic formation.
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Niel V, Milway VA, Dawe LN, Grove H, Tandon SS, Abedin TSM, Kelly TL, Spencer EC, Howard JAK, Collins JL, Miller DO, Thompson LK. Coordination “Oligomers” in Self-Assembly Reactions of Some “Tritopic” Picolinic Dihydrazone LigandsMononuclear, Dinuclear, Hexanuclear, Heptanuclear, and Nonanuclear Examples. Inorg Chem 2007; 47:176-89. [DOI: 10.1021/ic7016787] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Virginie Niel
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Victoria A. Milway
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Louise N. Dawe
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Hilde Grove
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Santokh S. Tandon
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Tareque S. M. Abedin
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Timothy L. Kelly
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Elinor C. Spencer
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Judith A. K. Howard
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Julie L. Collins
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - David O. Miller
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
| | - Laurence K. Thompson
- Department of Chemistry, Memorial University, St. John's, Newfoundland A1B 3X7, Canada, University of Durham, South Road, Durham DH1 3LE, U.K., and Kent State University, Salem Campus, Salem, Ohio 44460
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Dey SK, Abedin TSM, Dawe LN, Tandon SS, Collins JL, Thompson LK, Postnikov AV, Alam MS, Müller P. Supramolecular Self-Assembled Polynuclear Complexes from Tritopic, Tetratopic, and Pentatopic Ligands: Structural, Magnetic and Surface Studies. Inorg Chem 2007; 46:7767-81. [PMID: 17696336 DOI: 10.1021/ic070336a] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polymetallic, highly organized molecular architectures can be created by "bottom-up" self-assembly methods using ligands with appropriately programmed coordination information. Ligands based on 2,6-picolyldihydrazone (tritopic and pentatopic) and 3,6-pyridazinedihydrazone (tetratopic) cores, with tridentate coordination pockets, are highly specific and lead to the efficient self-assembly of square [3 x 3] Mn9, [4 x 4] Mn16, and [5 x 5] Mn25 nanoscale grids. Subtle changes in the tritopic ligand composition to include bulky end groups can lead to a rectangular 3 x [1 x 3] Mn9 grid, while changing the central pyridazine to a more sterically demanding pyrazole leads to simple dinuclear copper complexes, despite the potential for binding four metal ions. The creation of all bidentate sites in a tetratopic pyridazine ligand leads to a dramatically different spiral Mn4 strand. Single-crystal X-ray structural data show metallic connectivity through both mu-O and mu-NN bridges, which leads to dominant intramolecular antiferromagnetic spin exchange in all cases. Surface depositions of the Mn9, Mn16, and Mn25 square grid molecules on graphite (HOPG) have been examined using STM/CITS imagery (scanning tunneling microscopy/current imaging tunneling spectroscopy), where tunneling through the metal d-orbital-based HOMO levels reveals the metal ion positions. CITS imagery of the grids clearly shows the presence of 9, 16, and 25 manganese ions in the expected square grid arrangements, highlighting the importance and power of this technique in establishing the molecular nature of the surface adsorbed species. Nanoscale, electronically functional, polymetallic assemblies of this sort, created by such a bottom-up synthetic approach, constitute important components for advanced molecule-based materials.
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Affiliation(s)
- Subrata K Dey
- Department of Chemistry, Memorial University, St. John's, Newfoundland, A1B 3X7, Canada
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Tandon SS, Bunge SD, Thompson LK. A tetradecanuclear copper dimeric macrocyclic complex with a body-centred heptanuclear core-structure and magnetism. Chem Commun (Camb) 2007:798-800. [PMID: 17308635 DOI: 10.1039/b612795a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
2,6-Diformyl-4-methylphenol and 1,3-diamino-2-hydroxypropane template condense in the presence of Cu(NO(3))(2) and azide to produce a 3 : 3 macrocyclic ring containing an unprecedented grouping of seven copper(ii) ions within the macrocyclic cavity, with the seventh metal completing a body-centred heptanuclear lattice.
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Affiliation(s)
- Santokh S Tandon
- Department of Chemistry, Kent State University Salem Campus, Salem, OH 44460, USA.
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Tandon SS, Dawe LN, Milway VA, Collins JL, Thompson LK. Linear copper ‘chain’ complexes with bulky tritopic hydrazone ligands—structural and magnetic studies. Dalton Trans 2007:1948-53. [PMID: 17702175 DOI: 10.1039/b618067a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tritopic 2,6-picolyl-bis-hydrazone ligands with bulky terminal groups derived from phenyl-pyridyl ketone do not form the expected [3 x 3] grids on reaction with copper(II), but instead form Cu8 'pinwheels', and in the present case linear trinuclear, pentanuclear and chain structures also. Direct bridging between copper ions occurs through micro2-N-N diazine groups, and longer O-C-N hydrazone connections, leading to moderately strong antiferromagnetic exchange between adjacent metal centres. Structural and magnetic properties are discussed in the context of specific orthogonal and non-orthogonal bridges, which can be distinguished and quantified.
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Affiliation(s)
- Santokh S Tandon
- Department of Chemistry, Kent State University, Salem Campus, Salem, OH 44460, USA.
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Tandon SS, Srivastava PP, Mukherjee SC, Saharan N. Acute toxicity of synthetic pyrethroids to Indian major carp, Catla catla L. Bull Environ Contam Toxicol 2005; 74:610-3. [PMID: 15903198 DOI: 10.1007/s00128-005-0627-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Affiliation(s)
- S S Tandon
- Central Institute of Fisheries Education, Deemed University, ICAR, Seven Bungalows, Versova, Mumbai 400 061 (MS), India
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McKee V, Tandon SS. An octacopper(II) complex with .mu.5-oxo, and tripod-like perchlorate ligands; formation and x-ray structure of the [Cu4(L)O(ClO4)]2(ClO4)2.2H2O dimer. Inorg Chem 2002. [DOI: 10.1021/ic00314a002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Tandon SS, Thompson LK, Bridson JN. Dinuclear copper(II) and mixed-valence copper(II)-copper(I) complexes of 34-membered macrocyclic ligands (H2M1, H2M2) capable of forming endogenous phenolate and pyridazino bridges. X-ray crystal structures of the dinuclear copper(II) complexes [Cu2M1][BF4]2.cntdot.H2O and [Cu2M2][BF4]2.cntdot.CH3OH, which exhibit a remarkable ligand twist. Inorg Chem 2002. [DOI: 10.1021/ic00053a006] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tandon SS, Thompson LK, Bridson JN, McKee V, Downard AJ. Dinuclear copper(II) and polymeric tetranuclear copper(II) and copper(II)-copper(I) complexes of macrocyclic ligands capable of forming endogenous alkoxide and phenoxide bridges. Structural, magnetic, and electrochemical studies. Inorg Chem 2002. [DOI: 10.1021/ic00048a035] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Tandon SS, Mandal SK, Thompson LK, Hynes RC. Copper coordination chemistry of novel octadentate, tetranucleating, bis(diazine) ligands. Structural and magnetic properties of tetranuclear complexes involving a rectangular array of copper(II) centers. Inorg Chem 2002. [DOI: 10.1021/ic00037a041] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tandon SS, Thompson LK, Bridson JN, Benelli C. Hexanuclear and Dodecanuclear Macrocyclic Copper(II) and Nickel(II) Complexes with Almost Planar "Benzene-like" Metal Arrays. Inorg Chem 2002. [DOI: 10.1021/ic00126a022] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tandon SS, Chen L, Thompson LK, Bridson JN. Dinuclear copper(II) complexes of the tetradentate thiadiazole ligands BPMTD (2,5-bis((2-pyridylmethyl)thio)thiadiazole) and BPTD (2,5-bis(2-pyridylthio)thiadiazole). X-ray structures of [Cu2(BPTD)(.mu.2-Br)2Br2] and [Cu(BPMTD)Cl2]n and spectroscopic, electrochemical, and magnetic studies. Inorg Chem 2002. [DOI: 10.1021/ic00081a016] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chen L, Thompson LK, Tandon SS, Bridson JN. Synthetic, structural, and spectroscopic studies on copper(II), copper(I), and silver(I) complexes of a series of pyridazinophane and phthalazinophane macrocycles. Unusual extended metallocyclic structures. Inorg Chem 2002. [DOI: 10.1021/ic00071a016] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Tandon SS, Thompson LK, Hynes RC. Binuclear lead(II) and copper(II) complexes of 1,4-dihydrazinophthalazine (DHPH). Stabilization of copper(II) in the presence of a hydrazine moiety and x-ray crystal structure and magnetic properties of [Cu2(DHPH)2 (H2O)2(ClO4)2](ClO4)2. Inorg Chem 2002. [DOI: 10.1021/ic00037a040] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tandon SS, Thompson LK, Bridson JN, Dewan JC. Dinuclear copper(II) and cobalt(II) complexes of the tetradentate ligand 1,2,4,5-tetrakis(benzimidazol-2-yl)benzene (BTBI): metallacyclic and nonmetallacyclic derivatives. X-ray crystal structures of [Cu2(BTBI)2Cl2][Cu2(BTBI)Cl2(DMF)4]Cl4.cntdot.12DMF and [Co2(BTBI)Br4].cntdot.4DMF. Inorg Chem 2002. [DOI: 10.1021/ic00079a011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tandon SS, Thompson LK, Manuel ME, Bridson JN. Magnetostructural Correlations in .mu.2-1,1-N3 Bridged, Dinuclear Copper(II) Complexes. 1. Ferromagnetic and Antiferromagnetic Coupling Associated with the Azide Bridge. X-ray Crystal Structures of [Cu2(DMPTD)(.mu.2-N3)(.mu.2-Cl)Cl2].cntdot.CH3CN, [Cu2(DMPTD)(.mu.2-N3)2(N3)2], [Cu2(DIP)(.mu.2-N3)(.mu.2-Cl)Cl2].cntdot.0.5CH3OH, [Cu2(PAP46Me-H)(.mu.2-N3)(N3)2].cntdot.0.33H2O, [Cu2(PAP)(.mu.2-N3)Cl3].cntdot.CH2Cl2, [Cu2(PAP)(.mu.2-N3)(N3)(NO3)(CH3OH)](NO3).cntdot.CH3OH, [Cu2(PPD3Me)(.mu.2-N3)Cl3(H2O)1.5], and [Cu2(PPD)(.mu.2-N3)(NO3)3(H2O)1.6]. Inorg Chem 2002. [DOI: 10.1021/ic00102a033] [Citation(s) in RCA: 281] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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McCrea J, McKee V, Metcalfe T, Tandon SS, Wikaira J. Geometric control of redox level in tetranuclear manganese and cobalt systems. Inorganica Chim Acta 2000. [DOI: 10.1016/s0020-1693(99)00361-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Thompson LK, Tandon SS, Lloret F, Cano J, Julve M. An Azide-Bridged Copper(II) Ferromagnetic Chain Compound Exhibiting Metamagnetic Behavior. Inorg Chem 1997; 36:3301-3306. [PMID: 11669995 DOI: 10.1021/ic970023n] [Citation(s) in RCA: 150] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The one-dimensional chain complex [Cu(2)(&mgr;(2)-1,1-N(3))(2)(&mgr;(2)-1,3-NO(3))(2)(&mgr;(2)-1,3-Me(3)NCH(2)CO(2))(2)](n)() (1) contains three different bridge groups, &mgr;(2)-1,1-azide (end-on), &mgr;(2)-nitrate, and &mgr;(2)-syn,syn-carboxylate, arranged so that the azide and carboxylate groups bridge equatorially and dictate the intrachain magnetic behavior between the copper magnetic orbitals. Variable-temperature magnetic susceptibility studies at low field, and magnetization studies at variable field, reveal dominant intrachain ferromagnetism (J = 26 cm(-)(1)) but also much weaker interchain ferromagnetism (Θ = 2.3 K) and antiferromagnetism (J(eff) = -0.18 cm(-)(1)). The structure has been rationalized in terms of a layered magnetic model with antiferromagnetic coupling between ferromagnetically coupled layers, leading to metamagnetic behavior. The intrachain ferromagnetism is explained satisfactorily using extended Hückel molecular orbital calculations, which show clearly that orbital countercomplementarity exists on the part of the two magnetic bridge groups (azide and carboxylate), despite the very large azide bridge angle (119.5 degrees ).
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Affiliation(s)
- Laurence K. Thompson
- Department of Chemistry, Memorial University, St. John's, Newfoundland, A1B 3X7 Canada, and Departament de Química Inorgànica, Facultat de Química de la Universitat de València, Dr. Moliner 50, 46100 Burjassot, València, Spain
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Sheppard CL, Tandon SS, Thompson LK, Bridson JN, Miller DO, Handa M, Lloret F. Polynuclear copper(II) complexes with μ2-1,1-azide bridges. Structural and magnetic properties. Inorganica Chim Acta 1996. [DOI: 10.1016/s0020-1693(96)05233-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Thompson LK, Mandal SK, Tandon SS, Bridson JN, Park MK. Magnetostructural Correlations in Bis(&mgr;(2)-phenoxide)-Bridged Macrocyclic Dinuclear Copper(II) Complexes. Influence of Electron-Withdrawing Substituents on Exchange Coupling. Inorg Chem 1996; 35:3117-3125. [PMID: 11666507 DOI: 10.1021/ic9514197] [Citation(s) in RCA: 325] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Macrocyclic dicopper(II) complexes derived from 2,6-di(R)formylphenols and various linking diamines are surveyed and their magnetic and structural properties assessed. For those systems with "flat" dinuclear centers and no electronic perturbations associated with electron-withdrawing ligands or ligand groups, the complexes exhibit a "straight-line" relationship between exchange integral and phenoxide bridge angle. Within the angle range 98.8-104.7 degrees, 11 complexes are included with -2J in the range 689-902 cm(-)(1). When electron-withdrawing species are present, either as ligands or as groups bound to the macrocycle itself, considerable suppression of the antiferromagnetic exchange component is observed. Single-crystal X-ray diffraction studies are reported for three complexes. [Cu(2)(L1)(H(2)O)(2)]F(2)(CH(3)OH)(2) (1) crystallized in the triclinic system, space group P&onemacr;, with a = 8.1878(5) Å, b = 9.0346(7) Å, c = 10.4048(7) Å, alpha = 103.672(6) degrees, beta = 101.163(5) degrees, gamma = 104.017(5) degrees, and Z = 1. [Cu(2)(L2)Cl(2)] [Cu(2)(L2) (H(2)O)(2)]Cl(ClO(4)).5.5H(2)O (2) crystallized in the monoclinic system, space group P2(1)/n, with a = 14.4305(5) Å, b = 24.3149(8) Å, c = 18.6584(8) Å, beta = 111.282(3) degrees, and Z = 4. [Cu(2)(L3)(H(2)O)(2)](BF(4))(2) (3) crystallized in the triclinic system, space group P&onemacr;, with a = 8.6127(4) Å, b = 8.6321(7) Å, c = 10.8430(10) Å, a = 74.390(10) degrees, beta = 86.050(10) degrees, gamma = 76.350(10) degrees, and Z = 2. Square pyramidal copper ion stereochemistries are observed in all cases, with axially coordinated halogens or water molecules. Strong antiferromagnetic exchange is observed for all complexes (-2J = 784(8) cm(-)(1), Cu-O-Cu 103.65(10) degrees (1); -2J = 801(11) cm(-)(1), Cu-O-Cu 102.4(3), 107.5(3), 102.9(3), 106.1(3) degrees (2); -2J = 689(3) cm(-)(1), Cu-O-Cu 98.8(4) degrees (3)). The presence of electron-withdrawing CN groups on the periphery of the macrocyclic ligand leads to substantially reduced antiferromagnetic exchange.
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Affiliation(s)
- Laurence K. Thompson
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, A1B 3X7 Canada
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Tandon SS, Thompson LK, Miller DO. A novel tetranuclear copper(II) complex with three different types of azide, exhibiting weak antiferromagnetic exchange. ACTA ACUST UNITED AC 1995. [DOI: 10.1039/c39950001907] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tandon SS, Thompson LK, Bridson JN. A dinuclear copper(II) complex bridged simultaneously by end-on azido, bromo and diazole (N2) groups exhibiting strong ferromagnetic exchange. X-Ray structure and magnetic properties. ACTA ACUST UNITED AC 1993. [DOI: 10.1039/c39930000804] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tandon SS, Thompson LK, Bridson JN, Dewan JC. Dinuclear cobalt(II) complexes of a polyhydroimidazole ligand. Dinuclear (2:1) non-metallocyclic derivatives and dinuclear (1:1) metallocyclic complexes with a large, unoccupied central cavity. CAN J CHEM 1992. [DOI: 10.1139/v92-352] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ligand BTIM (1,2,4,5-tetrakis(4,5-dihydro-imidazol-2-yl)benzene) reacts with cobalt(II) salts to form two series of complexes. The 1:1, dinuclear, metallocyclic derivatives [Co2(BTIM)2X2]X2 (X = Cl (I), Br (II)) involve two bis-dentate ligands in a metallocyclic structure with a large unoccupied cavity. The 2:1, binuclear derivatives [Co2(BTIM)X4] (X = Cl (III), Br (IV)) involve two metals bound to a single, bis-bidentate ligand. The crystal and molecular structures of II and III are reported. Compound II crystallized in the monoclinic system, space group P21/c, with a = 13.642(6) Å, b = 11.560(3) Å, c = 18.406(7) Å, β = 101.73(3)° and four formula units per unit cell. Refinement by full-matrix least squares gave final residuals of R = 0.060 and Rw = 0.062. Compound III crystallized in the triclinic system, space group [Formula: see text], with a = 8.367(2) Å, b = 14.254(3) Å, c = 7.649(2) Å, α = 100.99(2)°, β = 101.44(2)°, γ = 106.85(1)° and one formula per unit cell. Refinement by full-matrix least squares gave final residuals of R = 0.052 and Rw = 0.045. In the metallocyclic structure (II) the square-pyramidal cobalt(II) centres are separated by 7.599(4) Å, while in the 2:1 derivative the two tetrahedral cobalt(II) centres have a much larger separation (8.736(3) Å).
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Tandon SS, Thompson LK, Bridson JN. A novel antiferromagnetically coupled, dimeric, dodecanuclear copper(II) complex involving two macrocyclic ligands each with a ‘benzene-like’ arrangement of six copper centres. ACTA ACUST UNITED AC 1992. [DOI: 10.1039/c39920000911] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Mckee V, Tandon SS. Synthesis and characterisation of a series of tetra- and octa-copper(II) complexes with macrocyclic ligands. ACTA ACUST UNITED AC 1991. [DOI: 10.1039/dt9910000221] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Downard AJ, McKee V, Tandon SS. Binuclear manganese(II) and nickel(II) complexes with a potentially octadentate macrocyclic ligand (H4L1): synthesis and characterisation. X-ray crystal structures of [Mn2(H2L1 )(CH3COO)2]·2CH3OH and [Ni2(H2L1 )(H2O)2Cl2]·2H20. Inorganica Chim Acta 1990. [DOI: 10.1016/s0020-1693(00)80211-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tandon SS, McKee V. Lead(II) and barium(II) complexes of a potentially octadentate macrocyclic ligand (H4L), capable of providing endogenous alkoxy and phenoxy bridges. The X-ray crystal structures of [Pb(H4L)][ClO4]2, [Pb2(H2L)][ClO4]2, and [(H6L)(H2O)2][ClO4]2. ACTA ACUST UNITED AC 1989. [DOI: 10.1039/dt9890000019] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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McKee V, Tandon SS. X-Ray crystal structure and some properties of a tetranuclear, mixed-valence manganese complex of a macrocyclic ligand. ACTA ACUST UNITED AC 1988. [DOI: 10.1039/c39880001334] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tandon SS, Larkworthy LF. A facile synthesis and structure determination from 13c-nmr spectroscopy of a novel heterocycle 1,1′-ethylenebis[2,3,8,8a-tetrahydro-5,8a-dimethyl-1 H-imidazo[2,1-c][1,4]thiazine], a case of transannular stabilization. J Heterocycl Chem 1985. [DOI: 10.1002/jhet.5570220253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Tandon SS, Larkworthy LF. Synthesis and characterization of nickel(II) complexes with cyclic and linear Schiff-base ligands incorporating sulphur, nitrogen, and oxygen donor atoms. ACTA ACUST UNITED AC 1984. [DOI: 10.1039/dt9840002389] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ladd MFC, Larkworthy LF, Leonard GA, Povey DC, Tandon SS. Crystal and molecular structure of a complex bromide containing planar diaquadibromochromium(II) units. ACTA ACUST UNITED AC 1984. [DOI: 10.1039/dt9840002351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Babar MA, Larkworthy LF, Tandon SS. Chromium(II) chemistry. Part 15. Synthesis and magnetic properties of piperazinium, hydrazinium, and monoaryl and other substituted ammonium tetrachlorochromatest. ACTA ACUST UNITED AC 1983. [DOI: 10.1039/dt9830001081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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