Polymeric, Molecular, and Cation/Anion Arrangements in Chloro‐, Bromo‐, and Iododiruthenium(<scp>II</scp>,<scp>III</scp>) Carboxylate Compounds

Abstract

Abstract The synthesis and characterization of the anhydrous compounds [Ru 2 X(μ‐O 2 CR) 4 ] [R = CH 2 CH 2 OPh, X = Cl ( 1a ), Br ( 2a ), I ( 3a ); R = CMePh 2 , X = Br ( 5a ), I ( 6a )] and of the solvated complexes [Ru 2 X(μ‐O 2 CR) 4 (H 2 O)] [R = CH 2 CH 2 OPh, X = Cl ( 1b ), I ( 3b ); R = CMePh 2 , X = Cl ( 4b ), Br ( 5b ), I ( 6b )] are described. Thermogravimetric analyses have been used to confirm the anhydrous or solvated natures of the complexes. The crystal structures of 1b·2MeOH , 3b·0.5H 2 O , and 4b have been investigated by X‐ray diffraction and none of them shows the usual polymeric arrangement reported for tetracarboxylatodiruthenium( II , III ) compounds. The structure of 3b·0.5H 2 O consists of cationic and anionic units, [Ru 2 (μ‐O 2 CCH 2 CH 2 OPh) 4 (H 2 O) 2 ][Ru 2 I 2 (μ‐O 2 CCH 2 CH 2 OPh) 4 ], and represents the first reported crystal structure of a tetracarboxylato(iodo)diruthenium( II , III ) derivative. The structures 1b·2MeOH and 4b each show the presence of discrete dinuclear molecules. The crystal structure of [Ru 2 Cl(μ‐O 2 CCMePh 2 ) 4 (H 2 O)] demonstrates that diruthenium compounds with the same halide and carboxylate ligands may adopt polymeric or discrete molecular dispositions. Magnetic susceptibility measurements of the complexes in the 2−300 K range have been carried out. Complex 2a shows a strong antiferromagnetic coupling, consistent with the existence of linear chains in the solid state. The complexes [Ru 2 X(μ‐O 2 CR) 4 (H 2 O)] show weak through‐space antiferromagnetic coupling, in accordance with non‐polymeric structures. The magnetic behaviour of 1a , 3a , 5a , and 6a suggests a mixture of arrangements. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2003)