An efficient synthesis of 2-di-tert-butylphosphanylmethylpyrrole( HpyrmPtBu 2 ), by treating 2-dimethylaminomethylpyrrole( HpyrmNMe 2 )w ith tBu 2 PH at 135 8Ci nt he absence of any solvent,h as allowed the preparation of the new PGeP germyleneG e(pyrmPtBu 2 ) 2 (1), by treating [GeCl 2 (dioxane)] with LipyrmPtBu 2 ,i nw hich the Ge atom is stabilized by intramolecular interactions with one (solid state) or both (solution) of its phosphane groups.R eactions of germylene 1 with Group 10 metald ichlorido complexes containing easily displaceablel igandsh ave led to [MCl{k 3 P,Ge,P-GeCl(pyrmPtBu 2 ) 2 }] [M = Ni (2), Pd (3), Pt (4)], which have an unflawed square-planar metale nvironment.Treatmento fg ermylene 1 with [AuCl(tht)] (tht = tetrahydrothiophene) rendered[ Au{k 3 P,Ge,P-GeCl(pyrmPtBu 2 ) 2 }] (5), which is ar are case of aT -shaped gold(I) complex. The hydrolysis of 5 gave the linear gold(I) derivative [Au(kP-HpyrmPtBu 2 ) 2 ]Cl (6). Complexes 2-5 contain aP GeP pincer chloridogermyl ligandt hat arises from the insertionof the Ge atom of germylene 1 into aM ÀCl bond of the corresponding metal reagent. The bondingi nt hese molecules has been studied by DFT/NBO/QTAIM calculations. These results demonstrate that the great flexibility of germylene 1 makesi tabetter precursor to PGeP pincer complexes than the previouslyk nown germylenes of this type.[a] Prof.Supporting information (containingt he experimental details and analytical, spectroscopic, structural(XRD), and theoretical (DFT,QTAIM) and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

This review article collects and discusses the syntheses of the currently known metal‐free heavier tetrylenes having a PEP pincer topology (E = tetrel atom) as well as their transition metal derivative chemistry. To date, only five PGeP germylenes and two PSnP stannylenes have been isolated. These compounds have been successfully synthesized by treating GeCl2(diox) (diox = 1,4‐dioxane), GeCl2(NHC) (NHC = N‐heterocyclic carbene) or SnCl2 with two equivalents of an appropriate lithiated phosphine. Their transition metal chemistry is dominated by processes in which, in addition to the coordination of one or both phosphane groups, the E atom ends inserted into M–M or M–X (X = anionic group) bonds. Only in a few occasions a simple coordination of the tetrylene fragment (as a neutral two‐electron‐donor ligand) has been observed. The structural and bonding characteristics of the metal‐free PEP tetrylenes and of relevant examples of their transition metal derivatives are also surveyed.

A dipyrromethane-based PGeP germylene has allowed the synthesis of unusual tetrahedral copper(i) and T-shaped silver(i) and gold(i) germyl complexes.

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}].

A dipyrromethane-based germylene decorated with two phosphane groups has been used to prepare an unusual T-shaped palladium(0) containing a PGeP pincer germylene that acts as a Z-type ligand. This compound...