Reactions of 1–3-η-allyl-manganese and -rhenium tetracarbonyls with phosphines, phosphites, and triphenylarsine. The crystal and molecular structure of 1–3-η-allyldicarbonylbis(trimethyl phosphite)manganese(I)

Abstract

The complexes [M(η-C3H5)(CO)3L][M = Mn, L = PPh3, AsPh3, P(C6H11)3, PBun3, or PMePh2; M = Re, L = PPh3] and [M(η-C3H5)(CO)2L2][M = Mn, L = PMePh2, P(OMe)3, P(OEt)3, or ½ Ph2PCH2PPh2; M = Re, L = PPh3] have been prepared from [M(η-C3H5)(CO)4] using thermal or photolytic methods. Taking the allyl group as bidentate, the complexes are considered to possess pseudo-octahedral structures, the carbonyl ligands being facial in the tricarbonyls and cis in the dicarbonyls. The 1H n.m.r. spectra are characteristic of η3-allyl species and show strong 1H–31P coupling. The mass spectra of the complexes have also been obtained and fragmentation pathways suggested mainly on the basis of observed metastable peaks. Crystals of [Mn(η-C3H5)(CO)2{P(OMe)3}2] are monoclinic with a= 18.618(11), b= 9.218(7), c= 10.607(11), β= 102.1(1)°, Z= 4, and space group P21/a. 1 742 Independent reflections above background have been collected on a diffractometer and refined to R 0.059. The metal atom has a distorted octahedral environment, being bonded to two mutually trans phosphorus atoms [Mn–P 2.175(5) and 2.219(5)A], two cis carbonyls [Mn–C 1.75(2) and 1.83(2)A], and an allyl group [Mn–C 2.223(17), 2.114(14), and 2.229(13)A].