Synthesis and crystal structure of dinuclear [(thf)3YCl2{μ-P(H)C6H2-2,4,6-Me3}]2 with seven-coordinate yttrium atoms

The metathesis reaction of KP(H)Mes with YCl3 in tetrahydrofuran yields dinuclear [(thf)3YCl2{μ-P(H)Mes}]2 (1) with a yield of 26% (Mes = mesityl, C6H2-2,4,6-Me3). The seven-coordinate yttrium atoms exhibit pentagonal bipyramidal coordination spheres with bridging mesitylphosphanide substituents. The Y2PC fragments are nearly planar with an average Y–P bond length of 296.0 pm. The P-bound hydrogen atoms are perpendicular to these planes. The small 1J(P,H) coupling constant of 125 Hz is in agreement with the picture that the H atom binds mainly to the p-orbital of the phosphorus atom.