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

Abstract

The complexation behavior of the stable 2-phosphabutadienes 3a,b, [M(CO) 5 {(SiMe 3 ) 2 CdPsC-(OEt)dC(H)Ph}] (3a M ) Cr; 3b M ) W), is investigated in their reaction with [Fe 2 (CO) 9 ] (4), which yields the corresponding (η 4 -2-phosphabutadiene)tricarbonyliron complexes 5a,b, [Fe(CO) 3 {η 4 -(SiMe 3 ) 2 CdPsC(OEt)dC-(H)Ph[M(CO) 5 ]}] (5a M ) Cr; 5b M ) W). Single-crystal X-ray structural analyses of complexes 3b and 5b establish a s-trans 2-phosphabutadiene unit for the former complex and a s-cis configuration for the latter.

Metal carbonyl complexes of phosphaamidines. Coordinative integrity detected in C-amino(λ3,σ2)-phosphaalkene isomers coordinated through n(P) HOMO−1 donor orbitals

“…1,3-azaphosphaallyls of Mg, Ca, Sr, Ba, Li and Sn have been prepared by silyl migration (the N and P substituents are thereby always a TMS group). 11,12 This recent work follows on a more extensive exploration by many workers on metal complexes of tri-substituted analogues which lack an ionisable H atom and hence tend to be prepared exclusively in one tautomeric form, [13][14][15][16][17][18] including conventional phosphaalkenes, [19][20][21][22][23][24][25][26][27][28][29][30][31] phosphacumulenes, [32][33][34][35][36][37][38][39][40] alkoxy-("Becker") phosphaalkenes R′PC(R)OR″, [41][42][43][44] aminophosphaalkenes R′PC(R)NR″ 2 (ref. [45][46][47][48] and diaminophosphaalkenes R′PC(NR″ 2 ) 2 .…”