Coordination chemistry of P-rich phosphanes and silylphosphanes. XXIII - Reactions of (Bu2P)-Bu-t-P=P(Me)Bu-t(2) with (Et3P)(2)NiCl2 and [{eta(2)-C2H4}Ni(PEt3)(2)]

(Bu2P)-Bu-t-P=P(Me)Bu-t(2) (1) forms with (Et3P)(2)NiCl2 (2) and Na(Nph) th e [mu-(1,3: 2,3-eta-(Bu2P4Bu2)-Bu-t-Bu-t){Ni(PEt3)Cl}(2)] (3) as main produ ct. Using Na/Hg instead as reducing agent the Ni-0 compounds [{eta (2)-(Bu2 P)-Bu-t-P}Ni(PEt3)(2)] (4), [{eta (2)-(Bu2P)-Bu-t-P=P-(PBu2)-Bu-t}Ni(PEt3)( 2)] (5) and [(Et3P)Ni(mu -(PBu2)-Bu-t)](2) (6) with four-membered Ni2P2 rin g result. [{eta (2)-C2H4}Ni(PEt3)(2)] yields with 1 also 4. The compounds w ere characterized by H-1 and P-31{H-1} NMR investigations and 3 also by a s ingle crystal X-ray analysis. It crystallizes triclinic in the space group P (1) over bar with a = 1129.4(2), b = 1256.8(3), c = 1569.5(3) pm, alpha = 72.44(3)degrees, beta = 70.52(3)degrees and gamma = 74.20(3)degrees.