Donor-stabilized germylium cations. To the scheme of formation of bis(chelate) germylium ions using the complexes with lactamomethyl (С,О)-chelate ligand (enantolactam derivatives) as an example

Halogen exchange in complexes of hexacoordinate tin (LnCH2)2SnX2 and (LnCH2)2SnY2 containing lactamomethyl n-membered C,O-chelate ligands LnCH2 (n=5–7; X, Y = Cl, Br, I)

“…The Sn-Hal bond lengths in all studied complexes exceeded their typical values for tetracoordinate tin compounds by at least 0.25 Å, which facilitated the dissociation of these bonds in solution. This trend was similar to that observed for hexacoordinated organogermanium complexes [10,11], in which the energies of Ge-Cl and Ge-Br bonds were also much lower than those in tetracoordinate germanium compounds.…”

“…An important aspect of our ongoing studies on organic complexes of penta-and hexacoordinate (hypervalent) silicon, germanium and tin with C,O-chelating amidomethyl and lactamomethyl ligands (L n CH 2 , n = lactam ring size, [5][6][7][8] is the effect of the substituent nature on the structure and rigidity of the coordination environment around the central atom. The results of these studies are discussed in reviews [1][2][3][4] and research papers [5][6][7][8][9][10][11][12].…”

“…In particular, the stoichiometric composition and spatial arrangement of mono-and bidentate ligands in bis(lactamomethyl)germanes (L n CH 2 ) 2 GeXY depend on the nature of monodentate ligands [5,[13][14][15]. Reactions of dichlorides (L n CH 2 ) 2 GeCl 2 with LiX, AgX and Me 3 SiX (X = F, Br, I, OTf, ClO 4 ) yield disubstituted products cis-(L n CH 2 ) 2 GeX 2 when the nucleofugacity of the entering group (For Br -) is similar to that of the leaving group (Cl -).…”