Reaction of 1,2-dimethylhydrazine with the platinum hydroxo complex [(dppp)Pt(mu -OH)](2)(BF4)(2) gives the bridging 1,2-dimethylhydrazido(-2) product [(dppp)(2)Pt-2(mu-eta (2):eta (2)-MeNNMe)](BF4)(2) 1. Crystals of 1(.)Ch(2)Cl(2) from CH2Cl2/Et2O are monoclinic (C/2) with a = 19.690(1), b = 18.886(1), c = 17.170 (1) Angstrom, and beta = 92.111 (1)degrees. Treatment of [(dppp)Pt(mu -OH)](2)(OTf)(2) with 1,1-dimethylhydrazine gives [(dppp)(2)Pt-2(mu -OH)(mu -NHNMe2)](OTf)(2) 2. Crystals of 2(.)CH(2)Cl(2) from CH2Cl2/Et2O are triclinic (P-1) with a = 12.910 (3), b = 13.927(3), c = 17.5872 (3) Angstrom, alpha = 87.121(3), beta = 89.997(4), and gamma = 84.728(3)degrees. Reaction of [(dppp)Pt(mu -OH)](2)(OTf)(2) with 1 equiv of phenylhydrazine in CH2Cl2 gives [(dppp)(2)Pt-2(mu -OH)(mu -NHNHPh)](OTf)(2) 3. Two equivalents of phenylhydrazine with [(dppp)Pt(mu -OH)](2)(X)(2) gives [(dppp)Pt(mu -NHNHPh)](2)(X)(2) 4 (X = BF4, OTf). Crystals of 3(.)ClCH(2)CH(2)Cl from ClCH2CH2Cl/(Pr2O)-Pr-i are monoclinic (P2(1)/n) with a = 20.990(2), b = 13.098(1), c = 25.773 (2) Angstrom, and beta = 112.944(2)degrees. Crystals of 4(X = BF4)(.)ClCH(2)CH(2)Cl(.)2(' BuOMe) from ClCH2CH2Cl/' BuOMe are monoclinic (C2/m) with a = 30.508(1), b = 15.203(1), c = 19.049 (1) Angstrom, and beta = 118.505 (2)degrees.