An experimental and theoretical (DFT) investigation of the coordination mode of 2,4-dithiouracil (2,4-dtucH(2)) in copper(I) complexes with 1,2-bis(diphenylphosphanyl)benzene (dppbz): The crystal structures of [Cu(mu-Br)(dppbz)](2) and [CuBr(dppbz)(2,4-dtucH(2))] (EN)

Aslanidis, P. (EN)

Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας (EL)

Aslanidis, P. (EN)

Novel copper(I) mixed-ligand complexes containing 1,2-bis (diphenylphosphanyl) benzene (dppbz) and 2,4-dithiouracil (2,4-dtucH(2)) ligands have been synthesised by addition of the thione ligand to the dinuclear [Cu(mu-X)(dppbz)](2) intermediate in acetonitrile/methanol or acetone solution. The molecular structures of both the precursor [Cu(mu-Br)(dppbz)]2 and the [CuBr(dppbz)(2,4-dtucH(2))] complexes were established by single-crystal X-ray diffraction. Interestingly, the structure of the thione-free dimer involves two diphosphanechelated Cu-I centres bridged by two bromide ligands, thus forming a non-planar Cu2Br2 core. The structure of [CuBr(dppbz)(2,4-dtucH(2))] corresponds to a four-coordinate Cu-I centre in a tetrahedral coordination environment with the heterocyclic dithione ligand being coordinated to the metal centre in a unidentate fashion through its exocyclic sulfur donor atom. The structural, bonding and electronic properties of the model complexes [Cu(mu-X)(dppbz)](2) and [CuX(dppbz)(2,4-dtucH(2))] (X = Cl, Br, or I) are adequately described by DFT/B3LYP computational techniques. All model dinuclear [Cu(mu-X)(dppbz)](2) complexes exhibit pi-type MOs delocalised over the entire four-membered Cu(mu-X)(2)Cu ring, thereby accounting for the near equivalency of the CuX bonds. Moreover, the [Cu(mu-X)(dppbz)](2) dimers possess a sigma-type MO corresponding to weak Cu center dot center dot Cu bonding interactions, which further stabilize the Cu(mu-X)(2)Cu ring. According to our calculations, the interaction energies of the 2,4-dtucH(2) ligand with the Cu-I centre are predicted to be about 13-16 kcal mol(-1). The coordination of the 2,4-dtucH(2) ligand is further stabilized by an X center dot center dot H-N hydrogen bond that is perpendicular to the plane of the dppbz ligand. (EN)

copper (EN)

University of Ioannina

Repository of UOI Olympias

Σχολή Θετικών Επιστημών

Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά)

ΑΠΟΘΕΤΗΡΙΟ "ΟΛΥΜΠΙΑΣ"

Τμήμα Χημείας

European Journal of Inorganic Chemistry (EN)

English

2006

http://olympias.lib.uoi.gr/jspui/handle/123456789/9277

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