Chlormethylchlorphosphane R(Cl)PCH 2Cl - synthone für den aufbau von phosphaalkenen im metalltemplat

Abstract

On reaction of the chloromethylchlorophosphines R(Cl)PCH 2Cl (R  Cl, iPr, tBu, NEt 2, N( iPr) 2, NPh 2, O-2,6- iPr 2C 6H 3; 1– 7) with diiron enneacarbonyl the iron carbonyl complexes 8– 14 are formed in good yields. Dehalogenation of the phosphine complexes 9– 14 with Fe 2(CO) 9 affords the phosphaalkene clusters [μ 3,η 2-RP CH 2]Fe 3(CO) 10 ( 15– 19). If Fe 3(CO) 12 is used instead of Fe 2(CO) 9 for the dehalogenation of 10- 13 phosphinidene phosphaalkene clusters [μ 3,η 2-RPCH 2][μ 3-PR]Fe 3(CO) 9 ( 25– 28) and binuclear complexes with bridging RPCH 2 ligands ( 21– 24) or α-metallated phosphido-phosphine bridges ( 20) (μ 2-P(R) CH 2P(R)CH 2 (R  tBu)) are obtained. The crystal structure of 18 (R  Ph 2N; space group P2 1/ n) shows the phosphaalkene ligand to be twisted about the P C bond (dihedral angle N(1)P(1)C(31)Fe(3) 177.5(1)°) the CH 2 group being pyramidalized (H(31)C (31)H(32) 104.0°). In the binuclear complex 20 (space group P2 1/ c phosphinoalkyl unit of the μ 2,η 3-P (R)CH 2P(R)CH 2 ligand spans the FeFe bond forming a distorted four-membered FePCFe ring with a short PC bond (P(2)C(12) 176.5(4) pm). The PCP donor set is coordinated to Fe(1) within a strained four-membered P 2CFe chelate ring. Then η 1,η 2-RPCH 2 ligand (R  N( iPr) 2) in 23 with a short PC bond (P(1)C(1) 173.4(4) pm) bridges two iron atoms, a distorted, almost planar Fe 2P 2 ring being formed.