Reactions of Late First‐Row Transition Metal (Fe‐Zn) Dichlorides with a PGeP Pincer Germylene

The reactivity of the PGeP germylene 2,2’‐bis(di‐ iso propylphosphanylmethyl)‐5,5’‐dimethyldipyrromethane‐1,1’‐diylgermanium(II), Ge(pyrmP i Pr 2 ) 2 CMe 2 , with late first‐row transition metal (Fe‐Zn) dichlorides has been investigated. All reactions led to PGeP pincer chloridogermyl complexes. The reactions with FeCl 2 and CoCl 2 afforded paramagnetic square planar complexes of formula [MCl{κ 3 P , Ge , P ‐GeCl(pyrmP i Pr 2 ) 2 CMe 2 }] (M=Fe, Co). While the iron complex maintained an intermediate spin state ( S 1 ; μ eff =3.0 μ B ) over the temperature range 50–380 K, the effective magnetic moment of the cobalt complex varied linearly with temperature from 1.9 μ B at 10 K to 3.6 μ B at 380 K, indicating a spin crossover behavior that involves S 1/2 (predominant at T <180 K) and S 3/2 (predominant at T >200 K) species. Both cobalt(II) species were detected by electron paramagnetic resonance at T <20 K. The reaction of Ge(pyrmP i Pr 2 ) 2 CMe 2 with [NiCl 2 (dme)] (dme=dimethoxyethane) gave a square planar nickel(II) complex, [NiCl{κ 3 P , Ge , P ‐GeCl(pyrmP i Pr 2 ) 2 CMe 2 }], whereas the reaction with CuCl 2 involved a redox process that rendered a mixture of the germanium(IV) compound GeCl 2 (pyrmP i Pr 2 ) 2 CMe 2 and a binuclear copper(I) complex, [Cu 2 {μ‐κ 3 P , Ge , P ‐GeCl(pyrmP i Pr 2 ) 2 CMe 2 } 2 ], whose metal atoms are in tetrahedral environments. The reaction of the germylene with ZnCl 2 led to the tetrahedral derivative [ZnCl{κ 3 P , Ge , P ‐GeCl(pyrmP i Pr 2 ) 2 CMe 2 }].