Divalent Germanium Compound with a Radical-Anionic Ligand: Molecular Structures of (dpp-BIAN)^•-GeCl and Its Hydrochloration Products [(dpp-BIAN)(H)₂]^•+[GeCl₃]^- and [{(dpp-BIAN)(H)₂^•+}₂(Cl^-)]<sup>+</s

The germanium(II) compound (dpp-BIAN)GeCl (1), which contains the radical anion of dpp-BIAN can be prepared either by reacting free dpp-BIAN ligand with 2 equiv of GeCl2(1,4-dioxane) in Et2O or by metathetical reaction of the sodium salt of dpp-BIAN with germanium dichloride in Et2O or benzene. The reaction of benzene solutions of 1 with 2 or 3 equiv of HCl led to protonation of the dpp-BIAN ligand affording [(dpp-BIAN)(H)2]•+[GeCl3]- (2) and [{(dpp-BIAN)(H)2•+}2(Cl-)]+[GeCl3]- (3), which incorporate the radical cation of the protonated ligand. Compounds 1−3 have been characterized by elemental analysis, IR, UV−vis, and electron spin resonance (ESR) spectroscopy. Molecular structures of 1−3 were determined by single-crystal X-ray diffraction. In molecule 1, the Ge atom is positioned at the apex of the slightly distorted trigonal pyramid. The Ge−N bond lengths in 1 are 2.0058(19) and 2.004(2) Å. The molecular structure of 2 consists of contact ions [(dpp-BIAN)(H)2]+ and [GeCl3]-. In the molecular structure of 3, two radical cations of [(dpp-BIAN)(H)2]+ are “coordinated” by the chlorine anion. The ESR signal of 1 indicates the presence of a dpp-BIAN radical anion and shows a hyperfine structure due to the coupling of an unpaired electron to 14N, 73Ge, 35Cl, 37Cl, and 1H nuclei (AN = 0.48 (2 N), AGe = 0.96, ACl = 0.78 (35Cl), ACl = 0.65 (37Cl), AH = 0.11 (4 H) mT, g = 2.0014). Both 2 and 3 reveal ESR signals of radical cation [(dpp-BIAN)(H)2]•+ (septet, AN = 0.53, AH = 0.48 mT, g = 2.0031).