The chormium containing compounds useful in the present invention comprise the organophosphoryl chromium compounds disclosed in U.S. Pat. No. 3,985,676 (incorporated herein by reference) which comprise the reaction product of chromium trioxide with an organophosphorus compound having the formula: ##STR1## wherein R is alkyl, aralkyl, aryl, cycloalkyl or hydrogen, but at least one R is other than h