New complexes of Cu(I) and Ru(II) with elemental (white) phosphorus (P-4), [Cu(C5H-i-Pr-4)(eta(2)-P-4)], [Cu(C5H-i-Pr-4)(mu,eta(2:1)-P-4)Cu(C5H-i-Pr-4)], and [Ru(C5Me5)(PCy3)(eta(2)-P-4)Cl], are synthesized with tetraphosphorus molecule as bidentate eta(2)-ligand. The complexes are obtained by reacting elemental phosphorus with the Cu carbonyl(tetraisopropylcyclopentadienyl) complex [Cu(C5H-i-Pr-4)(CO)] or with Ru(II) (pentamethylcyclopentadienyl)(tricyclohexylphosphine) chloride, [Ru(C5Me5)(PCy3)Cl]. The structures and compositions of the obtained complexes are studied by H-1, P-31 NMR method and elemental analysis. The P-4 molecule is connected to Cu(I) and Ru(II) fragments through the P-P edge due to a side coordination.