Ditelluroether ligand bis(4-methoxyphenyltelluro)methane - synthesis, reaction with iodine and its ruthenium(II) complexes. Crystal structures of (4-MeOC6H4Te)(2)CH2, {4-MeO-C6H4Te(I-2)}(2)CH2 cis-[Ru(DMSO)(2)Cl-2(4-MeOC6H4Te)(2)CH2] and [(p-cymene)C

摘要

The reaction of chloroform with ArTe- Na+ (Ar = 4-MeOC6H4), generated in situ by borohydride reduction of Ar2Te2, results in a high purity sample of bis(4-methoxyphenyltelluro)methane (1) (yield similar to 90%). Its single crystal structure has been reported. The Te-C-Te angle is found to be 117(1)degrees. The oxidative addition of I-2 to 1 results in {4-MeO-C6H4Te(I-2)}(2)CH2 (1a), which is also characterized structurally. The iodine atoms at each Te atom occupy axial positions. The two Te-I bonds are longer than the other two. The intermolecular contacts of I(2) and I(4) with the neighbouring Te atoms lead to polymeric links of essentially Te-I-Te'-I' rectangular bridges tangles 89.07(3)-94.68(3)degrees. The complexes of 1 with Ru(II) viz. cis-[Ru(DMSO)(2)Cl-2(4-MeOC6H4Te)(2)CH2] (2) and [(p-cymene)Cl2Ru(mu-1)RuCl2(p -cymene)] (2a) are synthesized and characterized structurally. The geometry of Ru(II) in the complex 2 is distorted octahedral. (Ru-Te 2.598815)-2.6727(5) Angstrom; Te(1)-Ru(1)-Te(2)= 78.2(2)degrees; Te(1)-Ru(1)-Cl(2)= 76.6(2)degrees. The distortions are not shared equally by the two tellurium atoms. The Te(1) displays much larger distortions of cis angles than those involving Te(2). The Te-C(aromatic) distances are shorter than Te-C(alkyl) bond lengths. The 2a is the first example in which the ligand 1 is shown to coordinate in a bridging mode, i.e. with two Ru atoms (Ru-Te 2.6381(16)-2.5411(2) Angstrom). The Te(1)-C-Te(2) angle is 119.3(9)degrees. Similarly 2 is also the first example that has four membered chelate ring containing Ru and two Te atoms. (C) 2000 Elsevier Science S.A. All rights reserved. [References: 27]