%0 Journal Article
%T Oxidative Addition Reactions of I2 with [HIr4(CO)10-n(PPh3 )n(¦̀-PPh2)] (n = 1 and 2) and Crystal and Molecular Structure of [HIr4(¦̀-I)2(CO)7 (PPh3)(¦̀-PPh2)]
%A Braga
%A Dario
%A Grepioni
%A Fabrizia
%A Vargas
%A Maria D.
%A Ziglio
%A Claudio M.
%J Journal of the Brazilian Chemical Society
%D 2002
%I Sociedade Brasileira de Qu¨ªmica, SBQ
%R 10.1590/S0103-50532002000500024
%X the reactions of the cluster compounds [hir4(co)10-n(pph3 )n(¦̀-pph2)] [n = 0, (1); 1, (2) and 2, (3)] with i2 have been investigated. compound 1 does not react, however, the presence of pph3 in place of co ligand(s) activates the cluster. both compounds 2 and 3 react with i2 under mild conditions to give [hir4(¦̀-i)2(co)7(pph3)(¦̀-pph 2)] (4), as the result of oxidative addition of i2 and dissociation of two co ligands, or one co and one pph3 ligands, respectively. the molecular structure of 4, determined by an x-ray diffraction study, exhibits a butterfly arrangement of iridium atoms with the wings spanned by a ¦̀-pph2 ligand, the hinge bridged by a ¦̀-h ligand, two hinge to wing tip edges bridged by iodine atoms and all metal atoms bearing two co ligands, with the exception of one of the hinge atoms that contains a co and a pph3 ligands. this cluster exhibits the shortest average ir£¿ir bond length [2.698(2) £¿] observed so far for a derivative of 1 and this is in accord with the relatively high average oxidation state of its metal atoms (+1) for a carbonyl cluster compound.
%K iridium cluster
%K oxidative addition
%K iodine
%K x-ray molecular structure.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S0103-50532002000500024&lng=en&nrm=iso&tlng=en