A Zwitterionic Transition-Metal Complex:  Platinum−closo-Borate Coordination Synthesis, Structure, and DFT Calculations

Abstract

A zwitterionic platinum(IV) complex comprising a cationic transition-metal center and an anionic heteroborate cluster was synthesized and structurally characterized. On the basis of DFT calculations a dipole moment of 29.8 D was determined for this polar molecule.

Stannaborate Transition Metal Chemistry: Ligand Properties, Reactivity, and Density Functional Theory Calculations of Platinum and Palladium Complexes

“…The satisfactory reproduction of the X-ray structure of 7 by DFT calculations allows the evaluation of the dipole moment. An elongation of about 0.10 in the Pt À Sn bond length has been shown [9] to influence the dipole moment by less than 10 %. A dipole moment of 29.1 D is determined for the optimized structure of trans-[(Et 3 P) 2 Pt(SnB 11 H 11 )(CNtBu)] by calculation of the expectation value of the dipole operator in the DFT wave function (i.e.…”

“…[21] The calculations were performed with DFT methods, [22] which in the past have proved to be suitable for the theoretical description of transition metal compounds and have been employed on another Pt ± SnB 11 H 11 complex. [9] The structural data were used as starting vectors in C 1 symmetry to simultaneously optimize the electronic and geometric structure. The relevant interatomic distances of the calculated model are compared to the experimental results from the X-ray structure analysis in Table 2.…”

“…Comparable dipole moments for zwitterions have been found by AM1 calculations in tetraalkylammoniumarylborate compounds (Me 3 NÀC 6 H 4 ÀBnBu 3 : 20.0 D) and by DFT methods for platinum or rhodium closo-borate clusters ([(bipy')Pt(Bz)(Ph)(tBuÀNC)(SnB 11 H 11 )]: 28.9 D; [Cp*M(bipy')(SnB 11 H 11 )]: 25.7 D; bipy' 4,4'-di-tert-butyl-2,2'-bipyridine). [9,23] Reactivity of the hydride complex 6: We investigate here the stannaborate dianion ligand and the chemistry of its respec- 8 [10] 11.9 2041 214 9 À 2.6 1633 240…”

“…Complexes with a variety of transition metals (Fe, Ni, Mo, Rh, Ir, Pt) have been synthesized in excellent yield. [9,10,23] Herein, we present syntheses and reactions of platinum and palladium complexes of stannacloso-dodecaborate and the first results of studies on the properties of the [SnB 11 H 11 ] ligand.…”

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“…74 The new zwitterionic complex [Bu 3 NMe][Pt(bipyA)Ph(SnB 11 H 11 )] has been described, along with its reactivity with benzyl bromide to form a crystallographically characterised platinum(IV) product of oxidative addition. 75 In a related paper, a range of phosphineplatinum stanna-closo-dodecaboranes of general formulae [PtL 2 (SnB 11 H 11 ) 2 ] 2+ and [PtL 2 R(SnB 11 H 11 )] + have been isolated. 76 The synthesis and structural characterisation of the first discrete octahedral sandwich complex composed of two electroneutral trimeric B-hexamethyl-9-mercuracarborand-3 [9,12-(CH 3 ) 2 -C 2 B 10 H 8 Hg] 3 receptors which simultaneously co-ordinate an iodide ion in a sandwich fashion has been reported.…”