A reaction of the 44 electron cluster [Pt-3(mu-PPh2)(3)Ph(PPh3)(2)] (1) with wet AgBF4 afforded the cationic cluster [Pt-3(mu(2)-OH)(mu-PPh2)(2)(PPh3)(3)]BF4 (3(BF4)) which slowly transformed into [Pt3(mu(2)-Cl)(mu-PPh2)(2)(PPh3)(3)] BF4 (4(BF4)) upon recrystallization from CH2Cl2. These 44 electron clusters have been characterized by P-31\H-1\ NMR, and the crystal structure of 4(PF6) has been determined by X-ray diffraction, as well as that of [Pt-3(mu-PPh2)(2)I-2(PPh3) (3)] (5), which was obtained by recrystallization of the known cluster [Pt-3(mu(2)-I)(mu-PPh2)(2)(PPh3)(3)] I (2(I)) from toluene and represents a neutral formula isomer of the latter. In addition, we have prepared the adducts of cluster 1 containing the moieties [Cu(NCMe)(2)](+) and [Au(PPh3)](+) in 6 and 7, respectively, and on the basis of their spectroscopic data, it was concluded that these complexes have similar structures to that previously established for the adduct of 1 with Ag(TFA) (TFA=OC(O)CF3), [Pt3\mu(3)-Ag(TFA)\(mu-PPh2)(3)Ph(PPh3)(2)] (8). The cationic clusters in 3(BF4) and 4(BF4) react with Ag(TFA) to afford cationic adducts in [Pt-3\mu(3)-Ag(TFA)\(mu(2)-X)(mu-PPh2) (2)(PPh3)(3)] BF4 (9(BF4), X=OH; 10(BF4), X=Cl). The structure of the mixed-metal cluster [Pt-3(mu(3)-AgBF4)(mu(2)-I)(mu-PPh2)(2)(PPh3)(3)] BF4 (11(BF4)), obtained by reaction of the complex 2(I) with AgBF4, was determined by X-ray diffraction.