Heteronuclear-bridged rhodium clusters

A heteronuclear-bridged rhodium cluster compound having the generic formula

• Rh.sub.f (.mu.-ER.sub.2).sub.m (CO).sub.p (E'R'.sub.3).sub.q
• wherein E and E' each individually represent a Group VA element selected from the group consisting of phosphorus, arsenic or antimony;
• wherein R and R' each individually represent a monovalent organic radical selected from the group consisting of alkyl, cycloalkyl, aryl, alkoxy and aryloxy radicals;
• wherein f has a value of from 2 to 6, m has a value of from 1 to 6, p has a value of from 1 to 6 and q has a value of from 1 to 6.