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Evans DM, Hughes DD, Murphy PJ, Horton PN, Coles SJ, de Biani FF, Corsini M, Butler IR. Synthetic Route to 1,1′,2,2′-Tetraiodoferrocene That Avoids Isomerization and the Electrochemistry of Some Tetrahaloferrocenes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00256] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Podda E, Coles SJ, Horton PN, Lickiss PD, Bull OS, Orton JB, Pintus A, Pugh D, Carla Aragoni M, Davies RP. First example of solid-state luminescent borasiloxane-based chiral helices assembled through N-B bonds. Dalton Trans 2021; 50:3782-3785. [PMID: 33634815 DOI: 10.1039/d1dt00114k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction between differently substituted borasiloxanes and 2,5-bis(3-pyridylethynyl)thiophene provided the first example of luminescent borasiloxane-based chiral helices held together by N-B bonds. The starting building blocks and the helices were fully characterized, and the nature of the N-B bond rationalized by means of theoretical calculations.
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Butler IR, Evans DM, Horton PN, Coles SJ, Murphy PJ. 1,1′,2,2′-Tetralithioferrocene and 1,1′,2,2′,3,3′-Hexalithioferrocene: Useful Additions to Ferrocene Precursor Compounds. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00702] [Citation(s) in RCA: 4] [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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Elgar CE, Otaif HY, Zhang X, Zhao J, Horton PN, Coles SJ, Beames JM, Pope SJA. Iridium(III) Sensitisers and Energy Upconversion: The Influence of Ligand Structure upon TTA-UC Performance. Chemistry 2021; 27:3427-3439. [PMID: 33242225 DOI: 10.1002/chem.202004146] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/20/2020] [Indexed: 12/21/2022]
Abstract
Six substituted ligands based upon 2-(naphthalen-1-yl)quinoline-4-carboxylate and 2-(naphthalen-2-yl)quinoline-4-carboxylate have been synthesised in two steps from a range of commercially available isatin derivatives. These species are shown to be effective cyclometallating ligands for IrIII , yielding complexes of the form [Ir(C^N)2 (bipy)]PF6 (where C^N=cyclometallating ligand; bipy=2,2'-bipyridine). X-ray crystallographic studies on three examples demonstrate that the complexes adopt a distorted octahedral geometry wherein a cis-C,C and trans-N,N coordination mode is observed. Intraligand torsional distortions are evident in all cases. The IrIII complexes display photoluminescence in the red part of the visible region (668-693 nm), which is modestly tuneable through the ligand structure. The triplet lifetimes of the complexes are clearly influenced by the precise structure of the ligand in each case. Supporting computational (DFT) studies suggest that the differences in observed triplet lifetime are likely due to differing admixtures of ligand-centred versus MLCT character instilled by the facets of the ligand structure. Triplet-triplet annihilation upconversion (TTA-UC) measurements demonstrate that the complexes based upon the 1-naphthyl derived ligands are viable photosensitisers with upconversion quantum efficiencies of 1.6-6.7 %.
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Otaif HY, Adams SJ, Horton PN, Coles SJ, Beames JM, Pope SJA. Bis-cyclometalated iridium( iii) complexes with terpyridine analogues: syntheses, structures, spectroscopy and computational studies. RSC Adv 2021; 11:39718-39727. [PMID: 35494133 PMCID: PMC9044569 DOI: 10.1039/d1ra07213g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/02/2021] [Indexed: 12/28/2022] Open
Abstract
Two ligands based upon a 2,6-disubstituted pyridine bridge introduce bis-quinoxalinyl units in a fashion that yields analogues to the archetypal terdentate ligand, 2,2′:6′,2′′-terpyridine. The ligands were synthesised from the key intermediate 2,6-bis(bromoacetyl)pyridine: a new, high-yielding route is described for this reagent. Two ligand variants (differentiated by H/Me substituents on the quinoxaline ring) were explored as coordinating moieties for iridium(iii) in the development of luminescent complexes. Computational studies (DFT approaches employing B3LYP, B3LYP/LANL2DZ, and M062X/LANL2DZ levels) were used to investigate the geometric and coordination mode preferences of the new ligands and two possibilities arose from theoretical investigations: [Ir(N^N^N)2]3+ and [Ir(N^N^C)2]+, with the former predicted to be more energetically favourable. Upon synthesis and isolation of the Ir(iii) complexes, X-ray crystallographic studies revealed coordination spheres that were cyclometalated, the structures both showing a [Ir(N^N^C)2]PF6 arrangement. Further spectroscopic characterization via NMR confirmed the ligand arrangements in the complexes, and photophysical studies, supported by DFT, showed that a mixture of metal-to-ligand charge transfer (MLCT) and intra-ligand charge transfer (ILCT) character is likely to contribute to the emission features of the complexes, which phosphoresce orange-red (λem = 580–618 nm). The emission wavelength was influenced by the substituents on the quinoxaline ring (H vs. Me), thereby implying further tuneability is possible with future ligand iterations. Bis-terdentate Ir(iii) complexes incorporate two cyclometalated N^N^C bis-quinoxalinyl type ligands derived from the condensation of 2,6-bis(bromoacetyl)pyridine and different o-phenylenediamines.![]()
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Yan B, Horton PN, Weston SC, Russell AE, Grossel MC. Novel TCNQ-stacking motifs in (12-crown-4)-complexes of alkali metal TCNQ salts. CrystEngComm 2021. [DOI: 10.1039/d1ce01075a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An unusual crossed dimer motif is present in the solid state in the infinite TCNQ˙− columns of the bis-12-crown-4 complexes of Li and NaTCNQ.
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Butler IR, Beaumont M, Bruce MI, Zaitseva NN, Iggo JA, Robertson C, Horton PN, Coles SJ. Synthesis and Structures of 1,1′,2-Tribromoferrocene, 1,1′,2,2′-Tetrabromoferrocene, 1,1′,2,2′-Tetrabromoruthenocene: Expanding the Range of Precursors for the Metallocene Chemist’s Toolkit. Aust J Chem 2021. [DOI: 10.1071/ch19184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The synthesis, characterisation, and isolation of 1,1′,2-tribromoferrocene and 1,1′,2,2′-tetrabromoferrocene, which are key synthons in ferrocene chemistry, are described. These compounds are prepared using α-halide assisted lithiation. The crystal structures of 1,1′,2-tribromoferrocene, 1,1′,2,2′-tetrabromoferrocene, 1,1′-dibromoruthenocene, and 1,1′,2,2′-tetrabromoruthenocene have been determined and are reported together with a brief discussion of the intramolecular forces involved in the crystal structures.
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Altahan MA, Beckett MA, Coles SJ, Horton PN. Oxidopolyborate chemistry: The self-assembled, templated, synthesis, and an XRD study of a 1-D coordination polymer, [Cu(en){B 6O 7(OH) 6}] .3H 2O (en = 1,2-diaminoethane). PHOSPHORUS SULFUR 2020. [DOI: 10.1080/10426507.2020.1804204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Stonelake T, Phillips KA, Otaif HY, Edwardson ZC, Horton PN, Coles SJ, Beames JM, Pope SJA. Spectroscopic and Theoretical Investigation of Color Tuning in Deep-Red Luminescent Iridium(III) Complexes. Inorg Chem 2020; 59:2266-2277. [PMID: 32013422 PMCID: PMC7145353 DOI: 10.1021/acs.inorgchem.9b02991] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Indexed: 12/03/2022]
Abstract
A series of heteroleptic, neutral iridium(III) complexes of the form [Ir(L)2(N^O)] (where L = cyclometalated 2,3-disubstituted quinoxaline and N^O = ancillary picolinate or pyrazinoate) are described in terms of their synthesis and spectroscopic properties, with supporting computational analyses providing additional insight into the electronic properties. The 10 [Ir(L)2(N^O)] complexes were characterized using a range of analytical techniques (including 1H, 13C, and 19F NMR and IR spectroscopies and mass spectrometry). One of the examples was structurally characterized using X-ray diffraction. The redox properties were determined using cyclic voltammetry, and the electronic properties were investigated using UV-vis, time-resolved luminescence, and transient absorption spectroscopies. The complexes are phosphorescent in the red region of the visible spectrum (λem = 633-680 nm), with lifetimes typically of hundreds of nanoseconds and quantum yields ca. 5% in aerated chloroform. A combination of spectroscopic and computational analyses suggests that the long-wavelength absorption and emission properties of these complexes are strongly characterized by a combination of spin-forbidden metal-to-ligand charge-transfer and quinoxaline-centered transitions. The emission wavelength in these complexes can thus be controlled in two ways: first, substitution of the cyclometalating quinoxaline ligand can perturb both the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital levels (LUMO, Cl atoms on the ligand induce the largest bathochromic shift), and second, the choice of the ancillary ligand can influence the HOMO energy (pyrazinoate stabilizes the HOMO, inducing hypsochromic shifts).
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Al-Taie ZS, Anetts SR, Christensen J, Coles SJ, Horton PN, Evans DM, Jones LF, de Kleijne FFJ, Ledbetter SM, Mehdar YTH, Murphy PJ, Wilson JA. Proline derived guanidine catalysts forge extensive H-bonded architectures: a solution and solid state study. RSC Adv 2020; 10:22397-22416. [PMID: 35514555 PMCID: PMC9054603 DOI: 10.1039/c9ra07508a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 02/25/2020] [Indexed: 11/21/2022] Open
Abstract
The preparation of a range of amino acid derived guanidine organocatalysts is reported together with their application to the Michael addition of 2-hydroxy-1,4-napthoquinone to β-nitrostyrene, achieving a maximum ee of 56%. Some insight into the mechanism was sought by using X-ray crystallography and a detailed study of the intra- and intermolecular hydrogen bonding is reported. Catalysts assemble! We present the design and synthesis of a large family of amino acid derived guanidine organic moieties as catalysts in the solution state and building blocks towards extended H-bonded architectures upon crystallisation.![]()
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Wootton TL, Porter JA, Grewal KS, Chirila PG, Forbes S, Coles SJ, Horton PN, Hamilton A, Whiteoak CJ. Merging Cu-catalysed C–H functionalisation and intramolecular annulations: computational and experimental studies on an expedient construction of complex fused heterocycles. Org Chem Front 2020. [DOI: 10.1039/d0qo00283f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A copper-catalysed protocol for the synthesis of fused dihydrobenzofuran-isoquinolone compounds through an intramolecular annulation of readily accessible benzamide substrates is reported, along with a full DFT study into the mechanism.
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Altahan MA, Beckett MA, Coles SJ, Horton PN. Oxidopolyborate anions templated by transition-metal complex cations: Self-assembled syntheses and structural studies (XRD) of [Co(NH3)6]2[B4O5(OH)4]3·11H2O, [Ni(phen)3][B7O9(OH)5].9.5H2O and [Zn(dac)2(H2O)2][B7O9(OH)5]·H2O. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.127071] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Beckett MA, Meena BI, Rixon TA, Coles SJ, Horton PN. Pentaborate(1-) Salts and a Tetraborate(2-) Salt Derived from C 2- or C 3-Linked Bis(alkylammonium) Dications: Synthesis, Characterization, and Structural (XRD) Studies. MOLECULES (BASEL, SWITZERLAND) 2019; 25:molecules25010053. [PMID: 31877919 PMCID: PMC6982793 DOI: 10.3390/molecules25010053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 12/18/2019] [Accepted: 12/21/2019] [Indexed: 11/26/2022]
Abstract
The synthesis of a number of pentaborate(1-) salts from cations arising from N-substituted α,α-, α,β-, and α,γ-diaminoalkanes has been attempted in aqueous solution from B(OH)3 and the appropriate diammine in a 10:1 ratio. Despite relatively mild work-up conditions the pentaborate(1-) salts prepared were not always as anticipated and the following compounds were isolated in good yield: [Me2NH(CH2)2NHMe2][B5O6(OH)4]2 (1), [Et2NH(CH2)2NHEt2][B5O6(OH)4]2 (2), [Et2NH2][B5O6(OH)4] (3), [Me2NH2][B5O6(OH)4] (4), [Me2NH(CH2)3NHMe2][B5O6(OH)4]2 (5), [Et2NH(CH2)3NHEt2][B5O6(OH)4]2 (6), [Me3NCH2CH=CH2][B5O6(OH)4] (7), and [Me3N(CH2)3NMe3] [B5O6(OH)4]2.0.5H2O (8). The tetraborate(2-) salt, [Me3N(CH2)2NMe3][B4O5(OH)4].2B(OH)3.2H2O (9) was obtained in moderate yield (41%) from a 3:1 reaction of B(OH)3 with [Me3N(CH2)2NMe3](OH)2. All compounds were characterized by spectroscopy (1H, 11B, 13C NMR and IR) and thermal gravimetric analysis (TGA). BET analysis on materials derived thermally from selected samples (1, 2, 6, 7) all had porosities of < 1 m2/g, demonstrating that they were non-porous. Single-crystal XRD structures were obtained for 2, 3, 7, 8 and 9 and all contain extensive H-bonded polyborate lattices.
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Beckett MA, Coles SJ, Horton PN, Rixon TA. Synthesis and XRD study of an C 2-linked bis(quaternary ammonium) pentaborate: [Me 3NCH 2CH 2NMe 3][B 5O 6(OH) 4] 2. PHOSPHORUS SULFUR 2019. [DOI: 10.1080/10426507.2019.1631308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Phillips KA, Stonelake TM, Horton PN, Coles SJ, Hallett AJ, O'Kell SP, Beames JM, Pope SJ. Dual visible/NIR emission from organometallic iridium(III) complexes. J Organomet Chem 2019. [DOI: 10.1016/j.jorganchem.2019.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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41
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Fugu MB, Ellaby RJ, O'Connor HM, Pitak MB, Klooster W, Horton PN, Coles SJ, Al-Mashhadani MH, Perepichka IF, Brechin EK, Jones LF. Mono- and ditopic hydroxamate ligands towards discrete and extended network architectures. Dalton Trans 2019; 48:10180-10190. [PMID: 31187830 DOI: 10.1039/c9dt01531k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A family of mono- and ditopic hydroxamic acids has been employed in the synthesis and structural and physical characterisation of discrete (0D) and (1- and 2-D) extended network coordination complexes. Examples of the latter include the 1-D coordination polymer {[Zn(ii)(L3H)2]·2MeOH}n (5; L3H2 = 2-(methylamino)phenylhydroxamic acid) and the 2-D extended network {[Cu(ii)(L2H)(H2O)(NO3)]·H2O}n (5; L2H2 = 4-amino-2-(acetoxy)phenylhydroxamic acid). The 12-MC-4 metallacrown [Cu(ii)5(L4H)4(MeOH)2(NO3)2]·3H2O·4MeOH (7) represents the first metal complex constructed using the novel ligand N-hydroxy-2-[(2-hydroxy-3-methoxybenzyl)amino]benzamide (L4H3). Variable temperature magnetic susceptibility studies confirm strong antiferromagnetic exchange between the Cu(ii) centres in 7. Coordination polymer 5 shows photoluminescence in the blue region (λPL∼ 421-450 nm) with a bathochromic shift of the emission (∼15-30 nm) from solution to the solid state.
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Child SN, Raychev R, Moss N, Howchen B, Horton PN, Prior CC, Oganesyan VS, Fielden J. Cobalt-based molecular electrocatalysis of nitrile reduction: evolving sustainability beyond hydrogen. Dalton Trans 2019; 48:9576-9580. [PMID: 31184345 DOI: 10.1039/c9dt00773c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Two new cobalt bis-iminopyridines, [Co(DDP)(H2O)2](NO3)2 (1, DDP = cis-[1,3-bis(2-pyridinylenamine)] cyclohexane) and [Co(cis-DDOP)(NO3)](NO3) (2, cis-DDOP = cis-3,5-bis[(2-Pyridinyleneamin]-trans-hydroxycyclohexane) electrocatalyse the 4-proton, 4-electron reduction of acetonitrile to ethylamine. For 1, this reduction occurs in preference to reduction of protons to H2. A coordinating hydroxyl proton relay in 2 reduces the yield of ethylamine and biases the catalytic system back towards H2.
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Christensen J, Horton PN, Bury CS, Dickerson JL, Taberman H, Garman EF, Coles SJ. Radiation damage in small-molecule crystallography: fact not fiction. IUCRJ 2019; 6:703-713. [PMID: 31316814 PMCID: PMC6608633 DOI: 10.1107/s2052252519006948] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 05/14/2019] [Indexed: 05/29/2023]
Abstract
Traditionally small-molecule crystallographers have not usually observed or recognized significant radiation damage to their samples during diffraction experiments. However, the increased flux densities provided by third-generation synchrotrons have resulted in increasing numbers of observations of this phenomenon. The diversity of types of small-molecule systems means it is not yet possible to propose a general mechanism for their radiation-induced sample decay, however characterization of the effects will permit attempts to understand and mitigate it. Here, systematic experiments are reported on the effects that sample temperature and beam attenuation have on radiation damage progression, allowing qualitative and quantitative assessment of their impact on crystals of a small-molecule test sample. To allow inter-comparison of different measurements, radiation-damage metrics (diffraction-intensity decline, resolution fall-off, scaling B-factor increase) are plotted against the absorbed dose. For ease-of-dose calculations, the software developed for protein crystallography, RADDOSE-3D, has been modified for use in small-molecule crystallography. It is intended that these initial experiments will assist in establishing protocols for small-molecule crystallographers to optimize the diffraction signal from their samples prior to the onset of the deleterious effects of radiation damage.
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Altahan MA, Beckett MA, Coles SJ, Horton PN. Copper(2+) complexes of hydroxyoxidopolyborates: Synthesis and characterization of [Cu(MeNHCH 2CH 2NMeH) 2(H 2O) 2][B 5O 6(OH) 4] 2.2B(OH) 3. PHOSPHORUS SULFUR 2019. [DOI: 10.1080/10426507.2019.1631307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Altahan MA, Beckett MA, Coles SJ, Horton PN. Copper(2+) Complexes of Hydroxyoxidoborates. Synthesis and Characterization of Two Clusters Containing the Hexaborate(2−) Ligand: [Cu(NH2CH2CH2NEt2){B6O7(OH)6}]·5H2O and [Cu(NH3)2{B6O7(OH)6}]·2H2O. J CLUST SCI 2019. [DOI: 10.1007/s10876-019-01519-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Arthurs RA, Hughes DL, Horton PN, Coles SJ, Richards CJ. Application of Transmetalation to the Synthesis of Planar Chiral and Chiral-at-Metal Iridacycles. Organometallics 2019. [DOI: 10.1021/acs.organomet.8b00905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Slater-Parry ME, Durrant JP, Howells JM, Pitak MB, Horton PN, Klooster WT, Coles SJ, O'Connor HM, Brechin EK, Barra AL, Jones LF. Crowding out: ligand modifications and their structure directing effects on brucite-like {M x(μ 3-OH) y} (M = Co(ii), Ni(ii)) core growth within polymetallic cages. Dalton Trans 2019; 48:1477-1488. [PMID: 30632582 DOI: 10.1039/c8dt04229b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Previous employment of the ligands 2-methoxy-6-[(methylimino)methyl]phenol (L1H) and 2-methoxy-6-[(phenylimino)methyl]phenol (L2H) has resulted in the self-assembly of pseudo metallocalix[6]arene complexes of general formulae: [M7(μ3-OH)6(Lx)6](NO3)y (M = Ni(ii), x = 1, y = 2 (1) and Co(ii/iii), x = 2, y = 3 (2)). Extrapolating upon this work, we report the coordination chemistry of ligands 2-methoxy-6-{[(2-methoxyphenyl)imino]methyl}phenol (L3H), 2-[(benzylimino)methyl]-6-methoxyphenol (L4H), 2-[(benzylamino)methyl]-6-methoxyphenol (L5H) and 2-[(benzylamino)methyl]-4-bromo-6-methoxyphenol (L6H), whose structures are modifications of ligands L1-2H. These ligands are employed in the synthesis and characterisation of the dimetallic complex [Ni(ii)2(L3)3(H2O)](NO3)·2H2O·3MeOH (3); the monometallic complexes [Ni(ii)(L4)2] (4) and [Co(iii)(L4)3]·H2O·MeOH (5a); and the tetranuclear pseudo metallocalix[4]arene complexes: [(NO3)⊂Co(ii)4(μ3-OH)2(L5)4(H2O)2](NO3)·H2O (6), [(NO3)⊂Ni(ii)4(μ3-OH)2(L5)4(H2O)2](NO3)·H2O (7) and [Ni(ii)4(μ3-OH)2(L6)4(NO3)2]·MeCN (8). The tetrametallic 'butterfly' core topologies in 6-8 are discussed with respect to their structural and topological relationship with their heptanuclear [M7] (M = Co(ii), Ni(ii)) pseudo metallocalix[6]arene ancestors (1 and 2).
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Yan B, Horton PN, Russell AE, Wedge CJ, Weston SC, Grossel MC. Crown ether alkali metal TCNQ complexes revisited – the impact of smaller cation complexes on their solid-state architecture and properties. CrystEngComm 2019. [DOI: 10.1039/c9ce00234k] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Water molecules play a key structure-organising role in the crystallisation of 15-crown-5 complexes of lithium and sodium TCNQ in the presence of excess TCNQ0.
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Geoghegan BL, Phonsri W, Horton PN, Orton JB, Coles SJ, Murray KS, Cragg PJ, Dymond MK, Gass IA. Hysteretic thermal spin-crossover in heteroleptic Fe(ii) complexes using alkyl chain substituted 2,2′-dipyridylamine ligands. Dalton Trans 2019; 48:17340-17348. [DOI: 10.1039/c9dt03412a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The complexes trans-[FeII(LC4)2(NCS)2] (1C4) and trans-[FeII(LC10)2(NCS)2] (1C10) undergo thermally hysteretic spin-crossover with T1/2 = 127.5 K and 119.0 K respectively.
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Groves LM, Williams CF, Hayes AJ, Ward BD, Isaacs MD, Symonds NO, Lloyd D, Horton PN, Coles SJ, Pope SJA. Fluorescent functionalised naphthalimides and their Au(i)–NHC complexes for potential use in cellular bioimaging. Dalton Trans 2019; 48:1599-1612. [DOI: 10.1039/c8dt04069a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A series of fluorescent gold(i)–NHC complexes have been developed and investigated as cell imaging agents.
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