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1.
Inorg Chem ; 51(1): 370-6, 2012 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-22136165

RESUMO

The reaction of Hg(OAc)(2) with 1,4-benzenedithiol in ethylenediamine at 80 °C yields [Hg(SC(6)H(4)S)(en)](n), while the reaction of Pb(OAc)(2) with 1,4-benzenedithiol in diethylenetriamine at 130 °C yields [Pb(SC(6)H(4)S)(dien)](n). Both products are crystalline materials, and structure determination by synchrotron X-ray powder diffraction revealed that both are essentially one-dimensional metal-organic polymers with -M-SC(6)H(4)S- repeat units. Diffuse reflectance UV-visible spectroscopy indicates band gaps of 2.89 eV for [Hg(SC(6)H(4)S)(en)](n) and 2.54 eV for [Pb(SC(6)H(4)S)(dien)](n), while density functional theory (DFT) band structure calculations yielded band gaps of 2.24 and 2.10 eV, respectively. The two compounds are both infinite polymers of metal atoms linked by 1,4-benzenedithiolate, the prototypical molecule for single-molecule conductivity studies, yet neither compound has significant electrical conductivity as a pressed pellet. In the case of [Pb(SC(6)H(4)S)(dien)](n) calculations indicate fairly flat bands and therefore low carrier mobilities, while the conduction band of [Hg(SC(6)H(4)S)(en)](n) does have moderate dispersion and a calculated electron effective mass of 0.29·m(e). Hybridization of the empty Hg 6s orbital with SC(6)H(4)S orbitals in the conduction band leads to the band dispersion, and suggests that similar hybrid materials with smaller band gaps will be good semiconductors.

2.
Acta Crystallogr B ; 67(Pt 5): 409-15, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21931210

RESUMO

The crystal structures of the isostructural title compounds poly[(µ-benzene-1,4-dithiolato)dithallium], Tl(2)(SC(6)H(4)S), and poly[(µ-benzene-1,4-diselenolato)dithallium], Tl(2)(SeC(6)H(4)Se), were solved by simulated annealing from high-resolution synchrotron X-ray powder diffraction. Rietveld refinements of an initial structure with one formula unit per triclinic cell gave satisfactory agreement with the data, but led to a structure with impossibly close non-bonded contacts. A disordered model was proposed to alleviate this problem, but an alternative supercell structure leads to slightly improved agreement with the data. The isostructural superlattice structures were confirmed for both compounds through additional data collection, with substantially better counting statistics, which revealed the presence of very weak superlattice peaks not previously seen. Overall, each structure contains Tl-S or Tl-Se two-dimensional networks, connected by phenylene bridges. The sulfur (or selenium) coordination sphere around each thallium is a highly distorted square pyramid or a 'see-saw' shape, depending upon how many Tl-S or Tl-Se interactions are considered to be bonds. In addition, the two compounds contain pairs of Tl(I) ions that interact through a closed-shell 'thallophilic' interaction: in the sulfur compound there are two inequivalent pairs of Tl atoms with Tl-Tl distances of 3.49 and 3.58 Å, while in the selenium compound those Tl-Tl interactions are at 3.54 and 3.63 Å.

3.
Inorg Chem ; 48(1): 183-92, 2009 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-19049423

RESUMO

Reactions of 2,6-dimethylphenyl phosphate (dmppH(2)) and 2,6-diisopropylphenyl phosphate (dippH(2)) with copper(II) precursors have been investigated in the presence of auxiliary N-donor ligands, and new structural types of copper phosphates have been isolated. Copper acetate reacts with dmppH(2) in the presence of either 3,5-di-tert-butyl pyrazole (dbpz) or 3,5-dimethyl pyrazole (dmpz), leading to the isolation of tetrameric complex [Cu(dmpp)(dbpz)](4) 1 and hexanuclear cage complex [Cu(6)(PO(4))(dmpp)(3)(OAc)(3)(dmpz)(9)] 2, respectively. Whereas compound 1 is a cubane-shaped cluster whose Cu(4)O(12)P(4) core resembles the double-4-ring (D4R) zeolite SBU, compound 2 is a novel hexanuclear copper complex with an unprecedented structure in metal phosphate chemistry. Use of bulkier dippH(2) in the above reactions, however, yielded metal-free acid-base complexes [(dippH)(dbpz)(dbpzH)] 3 and [(dippH)(dmpz)(dmpzH)] 4, respectively. The reactions carried out between copper acetate and dmppH(2) or dippH(2) in the presence of chelating ligand 1,10-phenanthroline produced structurally similar dimeric copper phosphates [Cu(phen)(dmpp)(CH(3)OH)](2).2CH(3)OH 5 and [Cu(phen)(dipp)(CH(3)OH)](2).2CH(3)OH 6 with a S4R SBU core. Changing the copper source to [Cu(2)(bpy)(2)(OAc)(OH)(H(2)O)].2ClO(4) and carrying out reactions both with dippH(2) and with dmppH(2) result in the formation of trinuclear copper phosphates [Cu(3)(bpy)(3)(dmpp)(2)(CH(3)OH)(3)].2ClO(4).2CH(3)OH 7 and [Cu(3)(bpy)(3)(dipp)(2)(CH(3)OH)(3)].2ClO(4).2CH(3)OH 8. The three copper ions in 7 and 8 are held together by two bridging phosphate ligands to produce a tricyclic derivative whose core resembles the 4=1 SBU of zeolites. Compounds 1-8 have been characterized by elemental analysis and IR, absorption, emission, and EPR spectroscopic techniques. The crystal structures of compounds 1, 2, 4, 5, 6, and 8 have also been established by single-crystal X-ray diffraction studies.

4.
Inorg Chem ; 45(23): 9154-6, 2006 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-17083206

RESUMO

Copper(II) perchlorate and (PhCONH)P(O)(OH)2 (H2bpa) react in methanol to yield [Cu(Hbpa)2]n, a novel layered solid that displays several interesting features. Unlike the previously reported copper phosphonates, a rare hexacoordination around the metal is observed in the title compound because of the amide C=O coordination to Cu in addition to the phosphoramidate P-O coordination. The six-membered chelate rings present in the title compound are made up of five different elements (Cu, P, C, N, and O).

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