Isolation of a germanium(ii) cation and a germylene iron carbonyl complex utilizing an imidazolin-2-iminato ligand

Abstract

A novel amino(imino)germylene was synthesised. Its conversion with B(C6F5)3 afforded a cyclic germanium(ii) cation in a methyl abstraction and ring closing reaction. The conversion with Fe2(CO)9 furnished a germylene iron carbonyl complex.

Isolation and Structure of Germylene‐Germyliumylidenes Stabilized by N‐Heterocyclic Imines

“…[10] These complexes (C)c an be regarded as dimers of the respective parent metallogermylene monocations that form aG e =Ge bond. [13,14] Notably,t his imino system was also implemented in the bis-(imino)germylene F [15] and the bis(imino)stannylenoid G [16] and the strongly related imidazolidine-2-iminato ligand (saturated in the ligand backbone) has been successfully used for the synthesis of ap hosphorus mononitride radical cation. Interestingly,t he solid structure of D was not reported before 2014.…”

“…[18] TheMBOs (Mayer bond orders) of the Ge1 À N imine bonds were both calculated to be 0.55 and this value is significantly smaller than the corresponding one of F (1.12), [18] and even reduced relative to the respective MBO of the germyliu-mylidene cation E (0.68), [14,18] and underlines the high dativebond character of the Ge1-N imine interactions.Incomparison, we determined MBOs of 0.89 for the Ge2 À N imine bonds in 3 + . [18] TheMBOs (Mayer bond orders) of the Ge1 À N imine bonds were both calculated to be 0.55 and this value is significantly smaller than the corresponding one of F (1.12), [18] and even reduced relative to the respective MBO of the germyliu-mylidene cation E (0.68), [14,18] and underlines the high dativebond character of the Ge1-N imine interactions.Incomparison, we determined MBOs of 0.89 for the Ge2 À N imine bonds in 3 + .…”

“…Interestingly, resonance structures of type A4,i nw hich formal positive charge is located at both imidazolium rings with af luoride anion coordinated to Ge1, have an on-negligible role in the description of 3 + (9.8 %). [15] This difference emphasizes the partial dative-bond character for the germanium-nitrogen atom interactions in 4 + .T he C NHC ÀN imine bonds [1.329(4) ,1.335(4) )] are elongated as compared to those of neutral iminogermylenes [1.296(3) , 1.273(2) ], [14,15] but fall well inside the range of those of the cationic compounds E [13,14] and 3 + (1.32-1.34 ), thus suggesting the delocalization of positive charge into the imidazoline rings.Interestingly,the triflato group in 4[BAr F 4 ]bridges the two germanium centers with the formation of two m 1 1 -type coordinative interactions between the metals and two oxygen atoms.The Ge-O triflate distances in 4 + [2.250(2) ,2.269(2) ] exceed the scope of typical Ge À Ob ond lengths (1.75-1.85 ) [22] and fall within the common range of Ge-O triflate distances (1.91-2.58 ), [23] thus demonstrating the bidentate coordination mode of the triflate ligand. [18] TheL UMO for 3 + is essentially the vacant p-type atomic orbital on the Ge II atom (Ge2) and supports 2 as an intermediate during the formation of 3 + ( Figure S30).…”

Facile Access to Stable Silylium Ions Stabilized by N-Heterocyclic Imines

“…The calculated chemical shift of optimized structure of 2 (8.1 ppm) corresponds well with the experimental value, supporting the presence of dimeric structure with a tetracoordinate silicon environment in 2[MeB(C6F5)3]2. The 19 F-NMR spectrum displays three distinct signals characteristic of [MeB(C6F5)3] due to the ortho, meta, and para F atoms of the C6F5 groups, which appear at similar shifts to those observed in III that have [MeB(C6F5)3] as a counterion [31,32]. Unfortunately, repeated efforts to grow single crystals of 2[MeB(C6F5)3]2 suitable for X-ray diffraction analysis were all unsuccessful.…”

“…During the last years, N-heterocyclic imines (NHIs) have been exploited for the syntheses of various unique main group compounds [28]. In Group 14, several metallylenes were synthesized by using NHIs as ligand [29][30][31][32], and two-coordinated metallyliumylidenes III (Figure 1) were also successfully isolated owing to stabilization of the NHI ligand by its high σ-donation together with delocalization of a positive charge around the imino fragment [31,32]. Shortly after, it was also demonstrated the NHIs effectively stabilize a spacer-separated bis(germyliumylidene) IV (Figure 1) [33].…”