Synthesis, structure determinations, and reduction of (C5H5)2Zr(Cl)CH2PMe2 and (C5Me5)2Zr(Cl)CH2PPh2

Article abstract of DOI:10.1021/om00127a021

The syntheses and X-ray crystallographic analyses of Cp₂Zr(Cl)CH₂PMe₂ (2) and (C₅Me₅)₂Zr(Cl)CH₂PPh₂ (3) are reported. The former is monoclinic of space group P2₁/n with a = 8.077 (3) ?, b = 14.896 (6) ?, c = 11.704 (3) ?, β = 99.27 (3)°, V = 1389.8 (8) ?³, and Z = 4. This compound is structurally very similar to Cp₂Zr(Cl)CH₂PPh₂ in possessing an extended, almost anti conformation for the Cl-Zr-C-P fragment about the Zr-C bond and a nonbonded Zr?P distance of 3.72 ?. The permethylcyclopentadienyl complex is monoclinic of space group P2₁/n with a = 10.285 (3) ?, b = 20.739 (5) ?, c = 14.078 (8) ?, β = 96.79 (4)°, V = 2982 (2) ?³, and Z = 4. In spite of the much bulkier ligands, this compound contains a gauche-like Cl-Zr-C-P system with a 31° dihedral angle and a relatively short 3.56-? Zr?P distance. One electron reduction of 2 produces a persistent P-bound Zr(III) species. In contrast, reduction of 3 gives a Zr(III) species lacking appreciable Zr-P interaction. The possible consequences of electronic and steric factors on these structures are discussed.