Small Platinum−Thallium Clusters Stabilized by Ethylenediamine, [(NC)5Pt−Tl(en)n−1] (n = 1−3) − Characterization in Solution and in the Solid State

Abstract

Three neutral binuclear platinum−thallium compounds containing a direct and “naked” (unsupported by ligands) metal−metal bond have been prepared in dimethyl sulfoxide (DMSO). The compounds have the formula [(NC)5Pt−Tl(en)n−1] (n = 1−3, for compounds 1, 2 and 3, respectively) and were found to exist in solution by means of multinuclear NMR (195Pt, 205Tl, 13C and 1H) and Raman spectroscopy. The compounds exhibit very large single bond 195Pt−205Tl spin‐spin coupling constants of 48−66 kHz. In addition, the solid state analogues of 1 and 3, [(NC)5Pt−Tl(DMSO)4](DMSO) and [(NC)5Pt−Tl(en)2](DMSO)2, were synthesized and their structures determined by single crystal X‐ray diffraction. The metal−metal bond lengths of Pt−Tl are 2.6131(4) Å and 2.6348(5) Å in compounds 1 and 3, respectively. Crystal data for compound 1: monoclinic, space group Cc (No. 9), Z = 4, a = 17.2367(14), b = 9.5560(11), c = 17.7941(15) Å, β = 100.551(10)°, V = 2881.4(5) Å3, T = 110(1) K; and for compound 3: monoclinic, space group P21 (No. 4), Z = 2, a = 9.3167(14), b = 12.3007(13), c = 11.4586(16) Å, β = 112.318(16)°, V = 1214.8(3) Å3, T = 110(1) K.

Synthesis and Structure of Monomeric and Platinum-Bonded (1,10-Phenanthroline)thallium Complexes

“…The preparation of Pt−Tl complexes with the N‐donor ligand ethylenediamine was described in our previous paper 4a. In a similar way, two new Pt−Tl complexes [(NC) 4 Pt−Tl(solv)] + ( 1a ) and [(NC) 5 Pt−Tl(solv)] ( 1b ) could be prepared; these two species were then treated with 1,10‐phenanthroline, whereby the complexes [(NC) 4 Pt−Tl(phen)(solv)] + ( 2a ), [(NC) 5 Pt−Tl(phen)(solv)] ( 2b ), [(NC) 4 Pt−Tl(phen) 2 (solv)] ( 3a ), and [(NC) 5 Pt−Tl(phen) 2 ] ( 3b ) in DMSO solution (Scheme ) were prepared.…”

“…The preparation and characterization of [(NC) 5 Pt−Tl(solv)] ( 1b ) was studied earlier4a and crystalline [(NC) 5 Pt−Tl(DMSO) 4 ] was obtained. When the solid [(NC) 5 Pt−Tl(DMSO) 4 ] was treated with 1,10‐phenanthroline at different molar ratios (cf.…”

“…The reactions were monitored by 205 Tl NMR spectroscopy. The solid compound [(NC) 5 Pt−Tl(DMSO) 4 ](DMSO) was obtained as described previously 4a. Two different routes were used to prepare compounds 2b and 3b : i) 49 mg of [Tl(DMSO) 6 ](ClO 4 ) 3 (0.05 mmol), 19 mg of K 2 Pt(CN) 4 (0.05 mmol), and 9 mg or 18 mg of 1,10‐phenanthroline (0.05 mmol or 0.1 mmol) for 2b and 3b , respectively, were added to 1 mL of DMSO in the presence of 50 m M NaCN.…”

4 Aluminium, gallium, indium and thallium

“…Complexes [(NC) 5 Pt-Tl(dmso) 5 ] and [(NC) 5 Pt-Tl(en) 2 (dmso) 2 ], were isolated and their structures determined by single crystal X-ray diffraction. 168 Three closely related heterodimetallic cyano complexes, [(NC) 5 Pt-Tl(CN) n ] nϪ (n = 1-3) were characterised using NMR and EXAFS data. 169 However, another cyano complex TlPt(CN) 5 has a very unusual structure indeed.…”

16 The noble metals

“…180 Further developments have come from the reactions of various Tl() complexes containing dmso and/or en with [Pt(CN) 4 ] 2Ϫ and cyanide to give such species as [(NC) 5 PtTl(en) 2 ] ϩ with direct Pt-Tl unsupported bonds that are also stable in solution. 181 Also, the first Pt()-Tl() unsupported bonds have been formed in the reaction of [Pt{PPh 2 (2-py)} 3 ] with TlX (X = NO 3 , OAc) in MeCN/MeOH giving [TlPt{PPh 2 (py)} 3 ] ϩ . The nitrate does not coordinate, but acetate remains bound to thallium, even in solution.…”