Equimolar and excess ratio reactions of IME3 and (IBu3)-Bu-i With the ligands 4,5-(P(E)Ph-2)(2t) (t =1,2,3-tria ole; E =O (1), S (2), Se(3)) were performed, showing a vast variety of coordination modes. The products obtained, Ir-2 k(2)-O,O'-[4,5-(P(O)Ph-2)(2)t (R = Me (4) Bu-i (5)), [AiR(2) k(3)-N,N', S-[4,5-(P(S)Ph-2)(2)t (mu-t)(2) (R = Me (6) R = Bu-i(7)), [AiMe(2) k(2)-N, Se-[4,5-(P(Se)Ph-2)(2)t (8), [Al{k(2)-N,Se-[4,5-(P(Se)Ph-2)(2)t 3(9), [AiR(2) k(2)-O,O'-[4,5-(P(O)-Ph-2)(2)t -(N'-AiR(3)) (R = Me (10), 'Bu (11)), and [AiR(2) k(2)-N,S-[4,5-(P(S)Ph-2)(2)t -(N-AiR(3)) (R = Me (12), R = iBu (13)) were characteri ed by spectroscopic methods, and the structures of 1, 4, 6, 7, 9, 10, and 12 were obtained through X-ray diffraction studies. Theoretical calculations were performed on the deprotonated ligands and on selected compounds to obtain information regarding the coordination variety observed for these compounds.