Towards multistranded molecular wires: syntheses, structures, and reactivities of tetraplatinum bis(polyynediyl) complexes with [upper bond 1 start]Pt-C(x)-Pt-(P(CH2)3P)2-Pt-C(x)-Pt-(P(CH2)3P[upper bond 1 end])2 cores (x = 4, 6, 8).