Preliminary investigations on the chemistry of (η⁴-1-phosphabutadiene)tricarbonyliron complexes. Synthesis and X-ray crystal structure analysis of a (η⁴-2-phosphabutadiene)tricarbonyliron complex

Reactivity of the Inversely Polarized Phosphaalkenes RP=C(NMe2)2 (R=tBu, Me3Si, H) towards Arylcarbene Complexes [(CO)5M=C(OEt)Ar] (Ar=Ph, M=Cr, W; Ar=2-MeC6H4, 2-MeOC6H4, M=W)

“…The ORTEP drawing (Figure 1) reveals 9 c as a Z ‐configured phosphaalkene, which is η 1 ‐ligated to a [(CO) 5 W] unit. The bond length W1−P1 (2.529(1) Å) is considerably longer than the W−P lengths in [W(CO) 5 { κ ‐ P ‐PhCH=CH‐P=CH‐CHMe 2 }] (2.472(2) Å)12 or in [W(CO) 5 { κ ‐ P ‐2‐ClC 5 H 4 P}] (2.457(2) Å)13 but markedly shorter than the corresponding bond length in [W(CO) 5 ‐ κ ‐ P ‐{Cp*(CO) 2 FeP=C(OEt)CH 3 }] (2.567(3) Å). The double bond length P1−C8 (1.694(2) Å) is well comparable to that in the latter complex (1.689(10) Å) and falls within the range usually observed in phosphaalkenes (1.66–1.71 Å).…”

Reactivity of the Metallophosphaalkene [(η5-C5Me5)(CO)2FeP=C(NMe2)2] towards Alkyl-, Aryl-, Alkenyl-, and Alkynylcarbene Complexes [(CO)5M=C(OEt)R] (M=Cr, W; R=CH3, Ph, CH=CHPh, C≡CPh)

“…Doublets in the 13 In order to confirm the geometry of the phosphaalkenyl ± iron fragment, a single-crystal X-ray structural analysis of 3 b was performed. The ORTEP drawing ( Figure 1) reveals a Zconfigured ferriophosphaalkene, which is h 1 -ligated to a [(CO) 5 [7] or in [W(CO) 5 {k-P-2-ClC 5 H 4 P}] [2.457(2) ], [8] but compares well with the corresponding W ± P bond lenght in [W(CO) 5 {k-P-(h 5 -tBu 2 C 2 P 3 )Fe(h 5 -tBu 3 C 3 P 2 )] [2.561 (2) ]. [9] The Fe ± P single bond length of 2.262(3) is markedly shorter than that in [(Z)-(h 5 -C 5 H 5 )(CO) 2 FePC(OSiMe 3 )-(tBu)] [2.298(1) ] [10] and resembles that in [(h 5 -C 5 Me 5 ) (CO) 2 FePC(SiMe 3 ) 2 ] [2.256 (2) ].…”

Syntheses and Structures of (η4-2-Phosphabutadiene)tricarbonyliron Complexes

“…The replacement of one carbon atom in butadiene by a two-coordinate phosphorus atom affords either a 1- or 2-phosphabutadiene . In spite of numerous studies, there are so far only a few established routes to 1-phosphabutadienes 2a-c or 2-phosphabutadienes. 2a,3a,b The tendency of free 1-phosphabutadienes to cyclize, , coupled with the low reactivity of kinetically-stabilized phosphabutadienes, 2a, has made it difficult to develop an extensive chemistry of these butadiene analogues. In 1991, Mathey et al 3b.…”

“…In spite of numerous studies, there are so far only a few established routes to 1-phosphabutadienes 2a-c or 2-phosphabutadienes. 2a,3a,b The tendency of free 1-phosphabutadienes to cyclize, , coupled with the low reactivity of kinetically-stabilized phosphabutadienes, 2a, has made it difficult to develop an extensive chemistry of these butadiene analogues. In 1991, Mathey et al 3b. described the synthesis of a stable coordinated 2-phosphabutadiene utilizing a phospha−Wittig reaction.…”