A major goal of this research was to study the reactions of a high-nuclearity Pd-Ni carbonyl precursor, [PPh 4 ] 4 [Pd 13 Ni 13 (CO) 34 ] ( 1 ) with trialkylphosphines including PMe 3 , PEt 3 , P i Pr 3 , P n Bu 3 , and PPh 3 in the presence of acetic acid or trimethylamineoxide (Me 3 NO). These reactions produced several high-nuclearity phosphine carbonyl clusters (i.e., ones arbitrarily considered to contain at least 12 metal-core atoms with M-M bonding). The first chapter gives an overview of cluster chemistry in terms of description and applications. The second chapter provides details of preparation, isolation, characterization, structural/bonding analysis, and Application of electron counting rules of clusters obtained from reactions of 1 with PEt 3 in the presence of acetic acid: namely Pd 9 Ni 9 (CO) 17 (PEt 3 ) 9 ( 2 ), Pd 34 (CO) 24 (PEt 3 ) 12 ( 3 ), Pd 23 (CO) 20 (PEt 3 ) 10 ( 4 ), Pd 16 (CO) 13 (PEt 3 ) 9 ( 5 ), and Pd 10 (CO) 12 (PEt 3 ) 6 ( 6 ). The last chapter provides similar details of clusters obtained from reactions of 1 with PMe 3 and P i Pr 3 in the presence of acetic acid or Me 3 NO: namely, Pd 16 (CO) 13 (PMe 3 ) 9 ( 7 ), Pd 10 (CO) 12 (P i Pr 3 ) 6 ( 8 ), Pd 10 (CO) 13 (P i Pr 3 ) 5 ( 9 ), and Pd 23 (CO) 20 (P i Pr 3 ) 8 ( 10 ), as well as attempts to obtain crystals from reactions with other trialkylphosphines. Both the composition and atomic arrangement of each cluster were conclusively established from an X-ray crystallographic determination via a SMART CCD area detector diffractometer (with Mo Kα radiation).