Coordination chemistry of P-rich phosphanes and silylphosphanes. XIX. [Co4P2(p(t)Bu(2))(2)(CO)(8)] and [{Co(CO)(3)}(2)(P4Bu4)-Bu-t] from Co-2(CO)(8) and (Bu2P)-Bu-t-P=P(Me)Bu-t(2)

Co-2(CO)(8) reacts with (Bu2P)-Bu-t-P=P(Me)Bu-t(2) yielding the compounds [ Co4P2((PBu2)-Bu-t)(2)(CO)(8)] (1) and [{eta(2)-(Bu2P)-Bu-t=P-P=(PBu2)-Bu-t) {Co(CO)(3)}(2)] (2a) cis, (2b) trans. In 1, four Co and two P atoms form a tetragonal bipyramid, in which two adjacent Co atoms are mu(2)-bridged by ( Bu2P)-Bu-t groups. Additionally, two CO groups are linked to each Co atom. In 2a and 2b, each of the Co(CO)(3) units is eta(2)-coordinated to the term inal P-2 units resulting in the cis- and trans-configurations 2a and 2b. 1 crystallizes in the orthorhombic space group Pnnm (No.58) with a = 879,41(5 ), b = 1199,11(8), c = 1773,65(11) pm. 2a crystallizes in the monoclinic sp ace group P2(1)/n (No.14) with a = 875,97(5), b = 1625,36(11), c = 2117,86( 12) pm, beta = 91,714(7)degrees 2b crystallizes in the triclinic space grou p P (1) over bar (No.2) with a = 812,00(10), b = 843,40(10), c = 1179,3(2) pm, alpha = 100,92(2)degrees, beta = 102,31(2)degrees, gamma = 102,25(2)deg rees.