Dinuclear platinum(II) complexes with bridging twofold deprotonated 2,2':6', 2''-terpyridne. New molecules with a 3,5-diplatinated-pyridil inner core: [Pt2(terpy-2H)(Me)(L2)], [Pt2(terpy-2H)(X)2(L)2] and [Pt2(terpy-2H)(H)2(L)2](L = neutral ligand; X = halide) - Crystal and molecular structure of [Pt2(terpy-2H)(Cl)2(PPh3)2]