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Synthesis and cluster structure distortions of biscarborane dithiol, thioether, and disulfide. Dalton Trans 2024; 53:4444-4450. [PMID: 38353929 DOI: 10.1039/d3dt04289h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
The synthesis and structural characterization of the first sulfur-containing derivatives of the C,C-biscarborane {ortho-C2B10}2 cluster - thiol, thioether, and disulfide - are reported. The biscarboranyl dithiol (1-HS-C2B10H10)2 exhibits an exceedingly long intracluster carbon-carbon bond length of 1.858(3) Å, which is attributed to the extensive interaction between the lone pairs of the thiol groups and the unoccupied molecular orbital of the carborane cluster. The structures of the doubly deprotonated biscarboranyl dithiolate anion (1-S-C2B10H10)22- with various counter cations feature an even longer carbon-carbon bond length of 2.062(10) Å within the cluster along with a short carbon-sulfur bond of 1.660(7) Å, both indicative of significant delocalization of electron density from the sulfur atoms into the cluster.
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2
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Redox-active carborane clusters in bond activation chemistry and ligand design. Chem Commun (Camb) 2023; 59:9918-9928. [PMID: 37522167 DOI: 10.1039/d3cc03011c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
Icosahedral closo-dodecaboranes have the ability to accept two electrons, opening into a dianionic nido-cluster. This transformation can be utilized to store electrons, drive bond activation, or alter coordination to metal cations. In this feature article, we present cases for each of these applications, wherein the redox activity of carborane facilitates the generation of unique products. We highlight the effects of exohedral substituents on reactivity and the stability of the products through conjugation between the cluster and exohedral substituents. Futher, the utilization of the redox properties and geometry of carborane clusters in the ligand design is detailed, both in the stabilization of low-valent complexes and in the tuning of ligand geometry.
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Activation of Alkynes by a Redox-Active Carboranyl Diphosphine and Formation of Boron-Containing Phosphacycles. Inorg Chem 2022; 61:18568-18573. [DOI: 10.1021/acs.inorgchem.2c02919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Tuning metal oxidation states in metal-organic framework (MOF) nodes by switching between two discrete linker photoisomers via an external stimulus was probed for the first time. On the examples of three novel photochromic copper-based frameworks, we demonstrated the capability of switching between +2 and +1 oxidation states, on demand. In addition to crystallographic methods used for material characterization, the role of the photochromic moieties for tuning the oxidation state was probed via conductivity measurements, cyclic voltammetry, and electron paramagnetic resonance, X-ray photoelectron, and diffuse reflectance spectroscopies. We confirmed the reversible photoswitching activity including photoisomerization rate determination of spiropyran- and diarylethene-containing linkers in extended frameworks, resulting in changes in metal oxidation states as a function of alternating excitation wavelengths. To elucidate the switching process between two states, the photoisomerization quantum yield of photochromic MOFs was determined for the first time. Overall, the introduced noninvasive concept of metal oxidation state modulation on the examples of stimuli-responsive MOFs foreshadows a new pathway for alternation of material properties toward targeted applications.
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Mechanistic investigations of alcohol silylation with isothiourea catalysts. Org Biomol Chem 2021; 19:10181-10188. [PMID: 34787145 DOI: 10.1039/d1ob01732b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mechanism of the asymmetric silylation of alcohols with isothiourea catalysts was studied by employing reaction progress kinetic analysis. These reactions were developed by the Wiskur group, and use triphenyl silyl chloride and chiral isothiourea catalysts to silylate the alcohols. While the order of most reaction components was as expected (catalyst, amine base, alcohol), the silyl chloride was determined to be a higher order. This suggested a multistep mechanism between the catalyst and silyl chloride, with the second equivalent of silyl chloride assisting in the formation of the reactive intermediate leading to the rate-determining step. Through the addition of additives and investigating changes in the silyl chloride, an understanding of the catalyst equilibrium emerged for this reaction and provided pathways for further reaction development.
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Bimetallic Ru-Pd and Trimetallic Ru-Pd-Cu Assemblies on the Carborane Cluster Surface. Inorg Chem 2021; 60:16911-16916. [PMID: 34710327 DOI: 10.1021/acs.inorgchem.1c02799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of well-defined heterometallic complexes remains a frontier challenge in inorganic chemistry. We report an approach that relies on the sequential insertion of electrophilic metal fragments into electron-rich Ru-B bonds of the η2-BB-carboryne complex (POBBOP)Ru(CO)2 [POBBOP = 1,7-OP(iPr)2-m-2,6-dehydrocarborane]. Utilizing this synthetic strategy, bimetallic (POBBOP)(Ru)(CO)2[Pd(PtBu3)] and trimetallic (POBBOP)(Ru)(CO)2[Pd(PtBu3)](CuBr) complexes were selectively prepared. Structural and theoretical analysis of the features of chemical bonding within Ru-B-B-Cu and Ru-B-B-Pd fragments is presented.
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Abstract
Carbon atom functionalization via generation of carbanions is the cornerstone of carborane chemistry. In this work, we report the synthesis and structural characterization of free ortho-carboranyl [C2B10H11]-, a three-dimensional inorganic analog of the elusive phenyl anion that features a "naked" carbanion center. The first example of a stable, discrete C(H)-deprotonated carborane anion was isolated as a completely separated ion pair with a crown ether-encapsulated potassium cation. An analogous approach led to the isolation and structural characterization of a doubly deprotonated 1,1'-bis(o-carborane) anion [C2B10H10]2 2-, which is the first example of a discrete molecular dicarbanion. These reactive carbanions are key intermediates in carbon vertex chemistry of carborane clusters.
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Abstract
We report metal-free bond activation by the carboranyl diphosphine 1-PtBu2-2-PiPr2-C2B10H10. This main group element system contains basic binding sites and possesses the ability to cycle through two-electron redox states. The reported reactions with selected main group hydrides and alcohols occur via the formal oxidation of the phosphine groups and concomitant reduction of the boron cage. These transformations, which are driven by the cooperation between the electron-donating exohedral substituents and the electron-accepting cluster, differ from those of "regular" phosphines and are reminiscent of oxidative addition to transition metal centers, thus representing a new approach to metal-free bond activation.
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Reaction of a ruthenium B-carboranyl hydride complex and BH3(SMe2): Selective formation of a pincer-supported metallaborane LRu(B3H8). Tetrahedron 2019. [DOI: 10.1016/j.tet.2019.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Manifestations of Weak O-H···F Hydrogen Bonding in M(H 2O) n(B 12F 12) Salt Hydrates: Unusually Sharp Fourier Transform Infrared ν(OH) Bands and Latent Porosity (M = Mg-Ba, Co, Ni, Zn). Inorg Chem 2018; 57:14983-15000. [PMID: 30444604 DOI: 10.1021/acs.inorgchem.8b02786] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Eight M(H2O) n(Z) salt hydrates were characterized by single-crystal X-ray diffraction (Z2- = B12F122-): M = Ca, Sr, n = 7; M = Mg, Co, Ni, Zn, n = 6; M = Ba, n = 4, 5. Weak O-H···F hydrogen bonding between the M(H2O) n2+ cations and Z2- resulted in room-temperature Fourier transform infrared (FTIR) spectra having sharp ν(OH) bands, with full widths at half max of 10-30 cm-1, which are much more narrow than ν(OH) bands in room temperature FTIR spectra of most salt hydrates. Clearly resolved νasym(OH/OD) and νsym(OH/OD) bands with Δν(OH) as small as 17 cm-1 and Δν(OD) as small as 11 cm-1 were observed (Δν(OX) = νasym(OX) - νsym(OX)). The isomorphic hexahydrates ( R3̅) have two fac-(H2O)3 sets of H2O ligands and nearly octahedral coordination spheres. They exhibited four resolvable ν(OH) bands, one νasym(OH)/νsym(OH) pair for H2O ligands with longer O(H)···F distances and one νasym(OH)/νsym(OH) pair for H2O ligands with shorter O(H)···F distances. The ν(OH) bands for the three H2O molecules with shorter, slightly stronger O(H)···F hydrogen bonds were broader, more intense, and red-shifted by ca. 25 cm-1 relative to the bands for the three other H2O molecules, the first time that such small differences in relatively weak O(H)···F hydrogen bonds in the same crystalline hexahydrate have resulted in observable IR spectroscopic differences at room temperature. For the first time room temperature ν(OH) values for salt hexahydrates showed the monotonic progression Mg2+ > Co2+ > Ni2+ > Zn2+, essentially the same progression as the p Ka values for these metal ions in aqueous solution. A further manifestation of the weak O-H···F hydrogen bonding in these hydrates is the latent porosity exhibited by Ba(H2O)5,8(Z), Sr(H2O) n,m(Z), and Ca(H2O)4,6(Z). Finally, the H2O/D2O exchange reaction Co(D2O)6(Z) → Co(H2O)6(Z) was ca. 50% complete in 1 h at 50 °C in N2/17 Torr H2O( g).
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Imido Group Interchange in Reactions of Zwitterionic Tantalum(V) Vinylimido Complexes and Nitriles. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Coordination Chemistry of Carborane Clusters: Metal-Boron Bonds in Carborane, Carboranyl, and Carboryne Complexes. COMMENT INORG CHEM 2018. [DOI: 10.1080/02603594.2018.1465939] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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13
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Expansion of the (BB) 〉metallacycle with coinage metal cations: formation of B-M-Ru-B (M = Cu, Ag, Au) dimetalacyclodiboryls. Chem Sci 2018; 9:2601-2608. [PMID: 29675252 PMCID: PMC5892348 DOI: 10.1039/c8sc00190a] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 02/03/2018] [Indexed: 01/12/2023] Open
Abstract
In this work, we introduce a novel approach for the selective assembly of heterometallic complexes by unprecedented coordination of coinage metal cations to strained single ruthenium-boron bonds on a surface of icosahedral boron clusters. M(i) cations (M = Cu, Ag, and Au) insert into B-Ru bonds of the (BB)-carboryne complex of ruthenium with the formation of four-membered B-M-Ru-B metalacycles. Results of theoretical calculations suggest that bonding within these metalacycles can be best described as unusual three-center-two-electron B-M···Ru interactions that are isolobal to B-H···Ru borane coordination for M = Cu and Ag, or the pairs of two-center-two electron B-Au and Au-Ru interactions for M = Au. These transformations comprise the first synthetic route to exohedral coinage metal boryl complexes of icosahedral closo-{C2B10} clusters, which feature short Cu-B (2.029(2) Å) and Ag-B (2.182(3) Å) bonds and the shortest Au-B bond (2.027(2) Å) reported to date. The reported heterometallic complexes contain Cu(i) and Au(i) centers in uncharacteristic square-planar coordination environments. These findings pave the way to rational construction of a broader class of multimetallic architectures featuring M-B bonds.
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Abstract
A new pathway of activation of C-H bonds of alkyl- and arylnitriles by a cooperative action of TaCl5 and PPh3 under mild conditions is reported. Coordination of nitriles to the highly Lewis acidic Ta(V) center resulted in an activation of their aliphatic and aromatic C-H bonds, allowing nucleophilic attack and deprotonation by the relatively weak base PPh3. The propensity of Ta(V) to form multiple bonds to nitrogen-containing ligands is an important driving force of the reaction as it led to a sequence of bond rearrangements and the emergence of, in the case of benzonitrile, a zwitterionic enediimido complex of Ta(V) through C═C double bond formation between two activated nitrile fragments. These transformations highlight the special role of the high-valent transition metal halide in substrate activation and distinguish the reactivity of the TaCl5-PPh3 system from both non-metal- and late transition metal-based frustrated Lewis pairs.
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Latent Porosity in Alkali-Metal M2B12F12 Salts: Structures and Rapid Room-Temperature Hydration/Dehydration Cycles. Inorg Chem 2017; 56:12023-12041. [DOI: 10.1021/acs.inorgchem.7b02081] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Rapid reversible borane to boryl hydride exchange by metal shuttling on the carborane cluster surface. Chem Sci 2017; 8:5399-5407. [PMID: 28970919 PMCID: PMC5609532 DOI: 10.1039/c7sc01846k] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 05/24/2017] [Indexed: 01/20/2023] Open
Abstract
In this work, we introduce a novel concept of a borane group vicinal to a metal boryl bond acting as a supporting hemilabile ligand in exohedrally metalated three-dimensional carborane clusters. The (POBOP)Ru(Cl)(PPh3) pincer complex (POBOP = 1,7-OP(i-Pr)2-m-2-carboranyl) features extreme distortion of the two-center-two-electron Ru-B bond due to the presence of a strong three-center-two-electron B-H···Ru vicinal interaction. Replacement of the chloride ligand with a hydride afforded the (POBOP)Ru(H)(PPh3) pincer complex, which possesses B-Ru, B-H···Ru, and Ru-H bonds. This complex was found to exhibit a rapid exchange between hydrogen atoms of the borane and the terminal hydride through metal center shuttling between two boron atoms of the carborane cage. This exchange process, which involves sequential cleavage and formation of strong covalent metal-boron and metal-hydrogen bonds, is unexpectedly facile at temperatures above -50 °C corresponding to an activation barrier of 12.2 kcal mol-1. Theoretical calculations suggested two equally probable pathways for the exchange process through formally Ru(0) or Ru(iv) intermediates, respectively. The presence of this hemilabile vicinal B-H···Ru interaction in (POBOP)Ru(H)(PPh3) was found to stabilize a latent coordination site at the metal center promoting efficient catalytic transfer dehydrogenation of cyclooctane under nitrogen and air at 170 °C.
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Comparison of the Coordination of B12F122–, B12Cl122–, and B12H122– to Na+ in the Solid State: Crystal Structures and Thermal Behavior of Na2(B12F12), Na2(H2O)4(B12F12), Na2(B12Cl12), and Na2(H2O)6(B12Cl12). Inorg Chem 2017; 56:4369-4379. [DOI: 10.1021/acs.inorgchem.6b02920] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Structures of M2(SO2)6B12F12 (M = Ag or K) and Ag2(H2O)4B12F12: Comparison of the Coordination of SO2 versus H2O and of B12F122– versus Other Weakly Coordinating Anions to Metal Ions in the Solid State. Inorg Chem 2016; 55:12254-12262. [DOI: 10.1021/acs.inorgchem.6b01980] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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(BB)-Carboryne Complex of Ruthenium: Synthesis by Double B-H Activation at a Single Metal Center. J Am Chem Soc 2016; 138:10531-8. [PMID: 27526855 PMCID: PMC4999960 DOI: 10.1021/jacs.6b05172] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Indexed: 12/22/2022]
Abstract
The first example of a transition metal (BB)-carboryne complex containing two boron atoms of the icosahedral cage connected to a single exohedral metal center (POBBOP)Ru(CO)2 (POBBOP = 1,7-OP(i-Pr)2-2,6-dehydro-m-carborane) was synthesized by double B-H activation within the strained m-carboranyl pincer framework. Theoretical calculations revealed that the unique three-membered (BB)>Ru metalacycle is formed by two bent B-Ru σ-bonds with the concomitant increase of the bond order between the two metalated boron atoms. The reactivity of the highly strained electron-rich (BB)-carboryne fragment with small molecules was probed by reactions with electrophiles. The carboryne-carboranyl transformations reported herein represent a new mode of cooperative metal-ligand reactivity of boron-based complexes.
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Opening of Carborane Cages by Metal Cluster Complexes: The Reaction of a Thiolate-Substituted Carborane with Triosmium Carbonyl Cluster Complexes. Inorg Chem 2016; 55:8207-13. [PMID: 27487332 DOI: 10.1021/acs.inorgchem.6b01403] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of Os3(CO)10(NCMe)2 with closo-o-(1-SCH3)C2B10H11 has yielded the complex Os3(CO)9[μ3-η(3)-C2B10H9(SCH3)](μ-H)2, 1, by the loss of the two NCMe ligands and one CO ligand from the Os3 cluster and the coordination of the sulfur atom and the activation of two B-H bonds with transfer of the hydrogen atoms to the cluster. Reaction of 1 with a second equivalent of Os3(CO)10(NCMe)2 yielded the complex Os3(CO)9(μ-H)[(μ3-η(3)-1,4,5-μ3-η(3)-6,10,11-C2B10H8S(CH3)]Os3(CO)9(μ-H)2, 2, that contains two triosmium triangles attached to the same carborane cage. The carborane cage was opened by cleavage of two B-C bonds and one B-B bond. The B-H group that was pulled out of the cage became a triply bridging group on one of the Os3 triangles but remains bonded to the cage by two B-B bonds. When heated to 150 °C, 2 was transformed into the complex Os3(CO)9(μ-H)[(μ3-η(3)-μ3-η(3)-C2B10H7S(CH3)]Os3(CO)9(μ-H), 3, by the loss of two hydrogen atoms and a rearrangement that led to further opening of the carborane cage. Reaction of 1 with a second equivalent of closo-o-(1-SCH3)C2B10H11 has yielded the complex Os3(CO)6)(μ3-η(3)-C2B10H9-R-SCH3) (μ3-η(3)-C2B10H10-S-SCH3)(μ-H)3, 4a, containing two carborane cages coordinated to one Os3 cluster. Compound 4a was isomerized to the compound Os3(CO)6(μ3-η(3)-C2B10H9-R-SCH3)(μ3-η(3)-C2B10H10-R-SCH3)(μ-H)3, 4b, by an inversion of stereochemistry at one of the sulfur atoms by heating to 174 °C.
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Formation of a Cationic Vinylimido Group upon C-H Activation of Nitriles by Trialkylamines in the Presence of TaCl5. Inorg Chem 2016; 55:5101-3. [PMID: 27172115 DOI: 10.1021/acs.inorgchem.6b00677] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report a new CH3CN activation mode where an imido group is directly formed by deprotonation of the nitrile coordinated to the highly Lewis acidic Ta(V) center. The unexpected deprotonation of TaCl5(CH3CN) by NEt3 resulted in isolation of the triethylammonium vinylimido complex [HNEt3][Ta(NC(CH2)NEt3)Cl5]. The reaction is proposed to proceed through rearrangement of the initial nucleophilic carbanion to the electrophilic azaallene/carbocation intermediate. The use of more sterically hindered (i-Pr)CN and weakly nucleophilic N(i-Pr)2Et resulted in the isolation of a vinylimido group formed upon dimerization of deprotonated nitriles, suggesting deprotonation as the first step of the transformation.
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Synthesis of the First Example of the 12-Vertex-closo/12-Vertex-nidoBiscarborane Cluster by a Metal-Free B−H Activation at a Phosphorus(III) Center. Chemistry 2016; 22:6764-7. [DOI: 10.1002/chem.201601194] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Indexed: 12/31/2022]
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Cage Opening of a Carborane Ligand by Metal Cluster Complexes. Chemistry 2016; 22:6501-4. [DOI: 10.1002/chem.201601075] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Indexed: 11/07/2022]
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25
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Metal- and Ligand-Centered Reactivity of meta-Carboranyl-Backbone Pincer Complexes of Rhodium. Organometallics 2016. [DOI: 10.1021/acs.organomet.5b00807] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Reversible water activation driven by contraction and expansion of a 12-vertex-closo-12-vertex-nido biscarborane cluster. Chem Commun (Camb) 2016; 52:12710-12713. [DOI: 10.1039/c6cc06955j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The metal-free reversible activation of H–OH bonds of water driven by the rearrangement of a boron cluster is presented.
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A Well-Defined Silica-Supported Tungsten Oxo Alkylidene Is a Highly Active Alkene Metathesis Catalyst. J Am Chem Soc 2013; 135:19068-70. [DOI: 10.1021/ja410052u] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Synthesis of a TREN in Which the Aryl Substituents are Part of a 45 Atom Macrocycle. J Am Chem Soc 2013; 135:15338-41. [DOI: 10.1021/ja408964g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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B(C6F5)3 Activation of Oxo Tungsten Complexes That Are Relevant to Olefin Metathesis. Organometallics 2013. [DOI: 10.1021/om4007906] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Addition of LiOHMT (OHMT = O-2,6-dimesitylphenoxide) to W(O)(CH-t-Bu)(PMe(2)Ph)(2)Cl(2) led to WO(CH-t-Bu)Cl(OHMT)(PMe(2)Ph) (4). Subsequent addition of Li(2,5-Me(2)C(4)H(2)N) to 4 yielded yellow W(O)(CH-t-Bu)(OHMT)(Me(2)Pyr)(PMe(2)Ph) (5). Compound 5 is a highly effective catalyst for the Z-selective coupling of selected terminal olefins (at 0.2% loading) to give product in >75% yield with >99% Z configuration. Addition of 2 equiv of B(C(6)F(5))(3) to 5 afforded a catalyst activated at the oxo ligand by B(C(6)F(5))(3). 5·B(C(6)F(5))(3) is a highly active catalyst that produces thermodynamic products (~20% Z).
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The Structure of (H3O)2B12F12·6H2O - a CCP Lattice of B12F122- Anions Intercalated with a Nonplanar Network of O-H···O Connected O6 Rings. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201101118] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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34
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35
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Bridged Heterocyclium Dicationic closo-Icosahedral Perfluoroborane, Borane, and Carborane Salts via Aqueous, Open-Air Benchtop Synthesis. Org Lett 2011. [DOI: 10.1021/ol200992c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Poly(perfluoroalkylation) of metallic nitride fullerenes reveals addition-pattern guidelines: synthesis and characterization of a family of Sc3N@C80(CF3)n (n = 2-16) and their radical anions. J Am Chem Soc 2011; 133:2672-90. [PMID: 21294511 DOI: 10.1021/ja109462j] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A family of highly stable (poly)perfluoroalkylated metallic nitride cluster fullerenes was prepared in high-temperature reactions and characterized by spectroscopic (MS, (19)F NMR, UV-vis/NIR, ESR), structural and electrochemical methods. For two new compounds, Sc(3)N@C(80)(CF(3))(10) and Sc(3)N@C(80)(CF(3))(12,) single crystal X-ray structures are determined. Addition pattern guidelines for endohedral fullerene derivatives with bulky functional groups are formulated as a result of experimental ((19)F NMR spectroscopy and single crystal X-ray diffraction) studies and exhaustive quantum chemical calculations of the structures of Sc(3)N@C(80)(CF(3))(n) (n = 2-16). Electrochemical studies revealed that Sc(3)N@C(80)(CF(3))(n) derivatives are easier to reduce than Sc(3)N@C(80), the shift of E(1/2) potentials ranging from +0.11 V (n = 2) to +0.42 V (n = 10). Stable radical anions of Sc(3)N@C(80)(CF(3))(n) were generated in solution and characterized by ESR spectroscopy, revealing their (45)Sc hyperfine structure. Facile further functionalizations via cycloadditions or radical additions were achieved for trifluoromethylated Sc(3)N@C(80) making them attractive versatile platforms for the design of molecular and supramolecular materials of fundamental and practical importance.
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Chemical tailoring of fullerene acceptors: synthesis, structures and electrochemical properties of perfluoroisopropylfullerenes. Chem Commun (Camb) 2011; 47:875-7. [DOI: 10.1039/c0cc03247f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Co-crystallization of octahedral and icosahedral fluoroanions in K3(AsF6)(B12F12) and Cs3(AsF6)(B12F12). Rare examples of salts containing fluoroanions with different shapes and charges. J Fluor Chem 2010. [DOI: 10.1016/j.jfluchem.2010.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Latent Porosity in Potassium Dodecafluoro-closo-dodecaborate(2−). Structures and Rapid Room Temperature Interconversions of Crystalline K2B12F12, K2(H2O)2B12F12, and K2(H2O)4B12F12 in the Presence of Water Vapor. J Am Chem Soc 2010; 132:13902-13. [DOI: 10.1021/ja105522d] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Bridged Heterocyclium Dicationic closo-Icosahedral Perfluoroborane, Borane, and Carborane Salts via Aqueous, Open-Air Benchtop Synthesis. Org Lett 2010; 12:2714-7. [DOI: 10.1021/ol100752y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Direct Perfluorination of K2B12H12 in Acetonitrile Occurs at the Gas Bubble−Solution Interface and Is Inhibited by HF. Experimental and DFT Study of Inhibition by Protic Acids and Soft, Polarizable Anions. J Am Chem Soc 2009; 131:18393-403. [DOI: 10.1021/ja9069437] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Structural and microstructural features of functional materials based on cuprates and manganites. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc2004v073n09abeh000920] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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X-ray structure and DFT study of C1-C60(CF3)12. A high-energy, kinetically-stable isomer prepared at 500 °C. Chem Commun (Camb) 2007:1650-2. [PMID: 17530089 DOI: 10.1039/b617489b] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The title compound, prepared from C(60) and CF(3)I at 500 degrees C, exhibits an unusual fullerene(X)12 addition pattern that is 40 kJ mol(-1) less stable than the previously reported C(60)(CF(3))12 isomer.
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Thermal instability of a cation-disordered NdBa2Cu3O7 superconductor. MENDELEEV COMMUNICATIONS 2004. [DOI: 10.1070/mc2004v014n04abeh001966] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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