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

• Published in: Chemistry : a European journal Vol. 27; no. 15; pp. 4985 - 4992
• Main Authors: Arauzo, Ana, Cabeza, Javier A., Fernández, Israel, García‐Álvarez, Pablo, García‐Rubio, Inés, Laglera‐Gándara, Carlos J.
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 12.03.2021; Wiley Subscription Services, Inc
• Subjects: Atomic properties; Chemistry; Chemistry, Multidisciplinary; Cobalt; Cobalt compounds; Coordination compounds; Copper chloride; Copper compounds; Dichlorides; Electron paramagnetic resonance; Electron spin resonance; first-row metals; Germanium; Germanium chlorides; germylenes; Iron chlorides; Magnetic moments; Nickel; Nickel chloride; PGeP pincers; Physical Sciences; pincer complexes; Science & Technology; spin crossover; Temperature; Transition metals; Zinc; Zinc chloride; LIGANDS; germylenes; first-row metals; COMPLEXES; PGeP pincers; spin crossover; pincer complexes
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202005289

The reactivity of the PGeP germylene 2,2’‐bis(di‐isopropylphosphanylmethyl)‐5,5’‐dimethyldipyrromethane‐1,1’‐diylgermanium(II), Ge(pyrmPiPr2)2CMe2, with late first‐row transition metal (Fe‐Zn) dichlorides has been investigated. All reactions led to PGeP pincer chloridogermyl complexes. The reactions with FeCl2 and CoCl2 afforded paramagnetic square planar complexes of formula [MCl{κ3P,Ge,P‐GeCl(pyrmPiPr2)2CMe2}] (M=Fe, Co). While the iron complex maintained an intermediate spin state (S1; μeff=3.0 μB) over the temperature range 50–380 K, the effective magnetic moment of the cobalt complex varied linearly with temperature from 1.9 μB at 10 K to 3.6 μB at 380 K, indicating a spin crossover behavior that involves S1/2 (predominant at T<180 K) and S3/2 (predominant at T>200 K) species. Both cobalt(II) species were detected by electron paramagnetic resonance at T<20 K. The reaction of Ge(pyrmPiPr2)2CMe2 with [NiCl2(dme)] (dme=dimethoxyethane) gave a square planar nickel(II) complex, [NiCl{κ3P,Ge,P‐GeCl(pyrmPiPr2)2CMe2}], whereas the reaction with CuCl2 involved a redox process that rendered a mixture of the germanium(IV) compound GeCl2(pyrmPiPr2)2CMe2 and a binuclear copper(I) complex, [Cu2{μ‐κ3P,Ge,P‐GeCl(pyrmPiPr2)2CMe2}2], whose metal atoms are in tetrahedral environments. The reaction of the germylene with ZnCl2 led to the tetrahedral derivative [ZnCl{κ3P,Ge,P‐GeCl(pyrmPiPr2)2CMe2}]. Pincer ligands: Paramagnetic (M=FeII, CoII) and diamagnetic (M=NiII, CuI, ZnII) mononuclear (M=FeII, CoII, NiII, ZnII) and binuclear (M=CuI) complexes supported by a PGeP pincer chloridogermyl ligand have been prepared from reactions of a dipyrromethane‐derived PGeP germylene with the corresponding metal(II) chlorides.