Selective Substitution of One of the Substituents on Germanium in Coordinatively Unsaturated Ruthenium Germyl Complexes
dataset
posted on 2012-04-09, 00:00 authored by Peter
D. W. Boyd, Michael C. Hart, Julian R. F. Pritzwald-Stegmann, Warren R. Roper, L. James WrightThe coordinatively unsaturated tri-p-tolylgermyl
complex RuCl(Ge[p-tolyl]3)(CO)(PPh3)2 (1) is obtained in good yield through
the reaction between HGe(p-tolyl)3 and
RuCl(Ph)(CO)(PPh3)2. On treatment of 1 with 1 equiv of NaS2CNR′2 (R′
= Et, Me), the chloride ligand is displaced and the corresponding
coordinatively saturated complexes Ru(κ2-S2CNR′2)(Ge[p-tolyl]3)(CO)(PPh3)2 (2a, R′ =
Et; 2b, R′ = Me) are formed. One of the PPh3 ligands in 2a is labile and undergoes substitution
readily on addition of CO to give the cis-dicarbonyl
complex Ru(κ2-S2CNEt2)(Ge[p-tolyl]3)(CO)2(PPh3) (3). On addition of NaS2CNMe2 to 2b, a PPh3 ligand is displaced by one sulfur atom
while the other sulfur atom displaces one of the p-tolyl groups on germanium to give Ru(κ2(Ge,S)-Ge[p-tolyl]2S2CNMe2)(κ2-S2CNMe2)(CO)(PPh3) (4). Complex 4 is
also formed on addition of excess NaS2CNMe2 to 1. Treatment of 1 with pyridine and ethanol under
ambient conditions also results in cleavage of one of the germyl p-tolyl groups, and the product formed is the coordinatively
unsaturated, ethoxy-substituted germyl complex RuCl(Ge[OEt][p-tolyl]2)(CO)(PPh3)2 (5). The ethoxy group in 5 is labile, and on contact
with n-propanol in solution, alkoxy group exchange
slowly occurs to give RuCl(Ge[OnPr][p-tolyl]2)(CO)(PPh3)2 (6). This reaction is reversible, and treatment of 6 with ethanol returns 5. In a related reaction, treatment
of 5 with water gives the hydroxy–germyl analogue
RuCl(Ge[OH][p-tolyl]2)(CO)(PPh3)2 (7). The single-crystal X-ray structures
of 1, 2a, 3, and 4 are presented.
