Synthesis and characterization of an organoyttrium dimer produced via an Arbuzov dealkylation reaction

The reaction of anhydrous YCl{sub 3} with 2 equiv of the sodium salt of the anionic tripod complex [({eta}{sup 5}-C{sub 5}H{sub 5})Co((CH{sub 3}CH{sub 2}O){sub 2}P=O){sub 3}]{sup -} (L{sub OEt}) in tetrahydrofuran, under anaerobic conditions, leads to the high-yield formation of [L{sub OEt}Y((C{sub 5}H{sub 5})Co(P(=O)(OEt){sub 2}){sub 2}(P(=O)(OEt)- (O))){sub 2}YL{sub OEt}] (1). The complex has been characterized by standard analytical techniques. Nuclear magnetic resonance spectroscopic studies show a reduction of local symmetry of one of the ligands. To clearly illustrate the structural features of the isolated complex in the solid state, a low-temperature data collection X-ray cryatallographic investigation was performed. This study reveals 1 to be a dimer with bridging phosphonate oxygens (monoclinic system, space group P2{sub 1}/n, with a = 12.261 (4) A b = 21.110 (5) A, c = 19.529 (5) A, {Beta} = 94.77 (2){degrees}, V = 5037 (6) A{sup 3}, Z = 2, T = 102 (2) K, and D{sub calcd} = 1.477 g/cm{sup 3}). The structure also shows that one of the phosphonate ethyl groups has been cleaved in the course of the reaction. Analysis of the volatiles generated during the reaction clearly shows the formation of ethyl chloride, indicating that 1 is produced in conjunction with the elimination of a phosphonate ethyl group in an Arbuzov-type dealkylation. 19 refs., 1 fig., 3 tabs.