Reactions of coordinated ligands : VIII. Synthesis and characterization of molybdenum carbonyl complexes of diphenylphosphinous acid and diphenylphosphinous acid derivatives☆

Abstract Several unexpected reactions have led to syntheses of cis -[Mo(CO) 4 ((PPh 2 ) 2 -E)] in which E = O, S, NH. The E = O complex was obtained from the reactions of several acid chlorides (CH 3 C(O)Cl, PCl 3 , (MeO)P(O)Cl 2 and [Mo(CO) 5 -(PMe 2 Cl)]) with [Et 3 NH] + cis -[Mo(CO) 4 ((PPh 2 O) 2 H)] − . The E = NH analog arose from the reaction of BF 3 · O(C 2 H 5 ) 2 with cis -[Mo(CO) 4 (PPh 2 NH 2 ) 2 ] and the E = S complex resulted from the reaction of H 2 S with cis -[Mo(CO) 4 (PPh 2 -Cl) 2 ]. The unsymmetrically substituted complex cis -[Mo(CO) 4 (PPh 2 OH)-(PPh 2 OCH 2 CH 3 )] was obtained from the reaction of cis -[Mo(CO) 4 (PPh 2 Cl) 2 ] with excess sodium ethoxide in ethanol. Cleavage of a PS bond in cis -[Mo-(CO) 4 ((PPh 2 ) 2 S] with NaOH in the presence of Et 4 N + Cl − yielded the unsymmetrical complex [Et 4 N] + cis -[Mo(CO) 4 ((PPh 2 O)(PPh 2 S)H)] − . Synthesis of cis -[Mo(CO) 4 ((PPh 2 O) 2 P(O)CH 2 Cl)] was accomplished by reacting (ClCH 2 )-P(O)(OH) 2 with cis -[Mo(CO) 4 (PPh 2 Cl) 2 ]. Multinuclear NMR ( 1 H, 13 C, 17 O, 31 P) and IR spectroscopy assisted in complex characterization. Conductance measurements on acetone solutions proved the complexes [Et 3 NH] + cis -[Mo(CO) 4 -((PPh 2 O) 2 E)] − , where E = H + , BF 2 + , and [Et 4 N] + cis -[Mo(CO) 4 ((PPh 2 O)-(PPh 2 Y)H)] − , where Y = O, S, to be 1/1 electrolytes.