MACROCYCLES INCORPORATING SULFUR AND NIDO-CARBORANE CAGES - REACTIVITY TOWARDS RH(III) AND IR(III) - MOLECULAR-STRUCTURES OF [IR(C5ME5)CL(7,8-MU-(SCH2CH2S)-7,8-C2B9H10)] AND 5)CL(7,8-MU-(S(CH2CH2(OCH2CH2)(3))S)-7,8-C2B9H10)]

The carboranyl bonded dithioether [7,8-mu-(S(CH2)(2)S)-7,8-C2B9H10](-) , [n6S2](-), and [7,8-mu-(S(CH2CH2(OCH2CH2)(3))S)-7,8-C2B9H10](-), [n1 5S2](-), are better metal-coordinating than their organic analogues. R eaction of [NMe4][n6S2] with [M-2(C5Me5)(2)Cl-4] (M = Rh, Ir) produces [M(C5Me5)Cl(n6S2)] (M = Rh, Ir) and reaction of [NMe4][n15S2] with [R h-2(C5Me5)(2)Cl-4] produces [Rh(C5Me5)Cl(n15S2)]. The carboranyl dithi oether ligands are able to remove one chloride ligand from the metal's coordination sphere, which is interpreted as if the negative charge o f the cluster partly resides on thioether. The crystal structure of [R h(C5Me5)Cl(n15S2)] and [Ir(C5Me5)Cl(n6S2)] have been solved. The ligan ds behave in a chelating mode providing two coordinating sites to the metal, the other three being provided by the carbocyclic ligand and th e remaining one by the chloride. The length of the spacer connecting t he two thioether groups produces significant geometrical differences i n the metal's surrounding specially in what concerns the S-M-S angle a nd the dihedral angle between the planes S(1), Ir, S(2) and S(1), S(2) , C(7) and C(8). (C) 1998 Elsevier Science S.A. All rights reserved.