Compounds of the type Tc2Cl4(PR(3))(4) (PR(3) = PEt(3), PMe(2)Ph, PMePh(2)) react with the molten formamidines HDPhF (HDPhF = diphenylformamidine) and HDTolF (HDTolF = di-p-tolylformamidine) to produce mixtures of tris- and tetrakis-bridged formamidinate complexes of ditechnetium. The displacement of chloride and phosphine by [DPhF](-) was accompanied by the oxidation of the dimetal core to produce the mixed-valent complexes Tc-2(DPhF)3Cl(2) (1) and Tc-2(DPhF)(4)Cl (2) in modest yield. The solid-state structures of the di-p-tolyl analog of 1, Tc-2(DTolF)(3)Cl-2 (1a), and Tc-2(DPhF)(4)Cl . C7H8 (2 . C7H8) have been determined by single crystal X-ray diffraction studies and are described in detail. The structure of 1a consists of three formamidinate ligands spanning the two technetium atoms. The two chloride ligands, which complete the coordination sphere, are bound equatorially at distances of 2.357(1) and 2.346(2) 8, from the metals. Though possessing no crystallographic symmetry, 1a approximates C-2 nu symmetry. The metal-metal bond length of 2.0937(6) Angstrom ranks among the shortest reported for technetium and is indicative of a Tc-Tc multiple bond. Compound 2 crystallizes with the Tc atoms colinear with a crystallographic 4-fold axis.