Novel derivatives of hypervalent germanium: synthesis, structure, and stability

Abstract

Syntheses of a series of novel germanium complexes, viz. RN(CH(2)CH(2)NC(6)F(5))(2)GeHal(2) (, R = Me, Hal = Cl; , R = Me, Hal = Br; , R = PhCH(2), Hal = Cl; , R = PhCH(2), Hal = Br), as well as MeN[CH(2)(2-C(4)H(3)N)](2)GeHal(2) (, Hal = Cl; , Hal = Br), by the reaction of GeHal(4) with dilithium salts of corresponding triamines are presented. PhCH(2)N(CH(2)CH(2)NSiMe(3))(2)GeCl(2) () was prepared analogously from triamine . Other approaches to the synthesized compounds were also tested. Unexpected complexes [N[upper bond 1 start](CH(2)CH(2)NSiMe(3))(2)Ge[upper bond 1 end](Hal)](2) (, Hal = Cl; , Hal = Br) were obtained by the reaction of GeHal(4) with dilithium salt of Me(3)SiN(CH(2)CH(2)NHSiMe(3))(2) (). DFT calculations on this reaction were carried out and discussed. Composition and structures of the novel compounds were established by elemental analyses, (1)H, (13)C, and (19)F NMR spectroscopy. The X-ray structural studies of and clearly indicated the presence of a transannular interaction N(ax)-->Ge for all studied compounds.

Novel Stannylenes Stabilized with Diethylenetriamido and ­Related Amido Ligands: Synthesis, Structure, and Chemical Properties

“…We found that monomeric stannylenes 7 and 8 reacted readily with methyl iodide in toluene at room temperature to give the expected pentacoordinate tin derivatives 15 and 16 (Scheme ), in which, apparently, an iodine atom is in trans position with respect to the donor nitrogen atom. This fact could be explained in terms of hypervalent bond (electron‐withdrawing substituent is in the trans position relative to the donor nitrogen atom) 13a. A similar result was obtained earlier for related germylenes 27…”

“…In this paper, the synthesis, structures and reactivities of novel stannylenes stabilized by diethylenetriamines 1 – 3 and triamine 4 with N 2 N bonding (two covalent and one donor bonds) to the central atom are discussed, together with the crystal structures of two diethylenetriamine ligands 1 14 and 2 13a containing electron‐withdrawing N ‐pentafluorophenylamide functionalities. Furthermore, the transamination reactions of Lappert's stannylene Sn[N(SiMe 3 ) 2 ] 2 11b with electron deficient amines, bis(pentafluorophenyl)amine ( 6 ) and N , N ′‐bis(pentafluorophenyl)phenylene‐1, 2‐diamine ( 5 ) (the precursor to a redox‐active ortho ‐phenylenediamido ligand developed in our laboratory15), are discussed.…”

Stabilized Germylenes Based on Diethylenetriamines and Related Diamines: Synthesis, Structures, and Chemical Properties

“…A white solid was separated by filtration, washed with diethyl ether (2 × 2 mL), and dried under vacuum to give 4 (0.30 g, 54 %) as a white solid. The 1 H and 13 C NMR spectra are in accord with literature data 24b . 1 H NMR (400 MHz, C 6 D 6 , 25 °C): δ = 1.93 (s, 3 H, NCH 3 ), 1.93–1.98, 2.20–2.25 (2 m, 4 H, 2 NCH 2 ), 2.83–2.69 (m, 4 H, 2 NCH 2 C 6 F 5 ) ppm.…”

“…Solvents were dried by standard methods and distilled prior to use. The starting materials were synthesized according to literature procedures: Ge[N(TMS) 2 ] 2 ,31 [GeCl 2 · C 4 H 8 O 2 ],32 LiN(TMS) 2 · Et 2 O,33 MeN(CH 2 CH 2 NHC 6 F 5 ) 2 ,34 BnN(CH 2 CH 2 NHC 6 F 5 ) 2 ,24b BnN(CH 2 CH 2 NHTMS) 2 ,24b H 2 (dpma),35 TMSN(CH 2 CH 2 NHTMS) 2 ,36 FcC(O)CH=CHPh,37 HN(C 6 F 5 ) 2 ,38 LiN(C 6 F 5 ) 2 ,38 and N , N′ ‐bis(pentafluorophenyl)benzene‐1,2‐diamine ( 1i ) 39. MeI (Aldrich), GeCl 4 (Aldrich), Et 2 S 2 (Aldrich), and 2,3‐dimethylbuta‐1,3‐diene (Aldrich) were distilled prior to use.…”

“…Toluene (5 mL) was added to the residue, and the precipitate was filtered. After removing all the volatiles in vacuo, a yellow oil was obtained, which corresponds to the starting amine 1b according to the NMR spectroscopic data 24b . 1 H NMR (400 MHz, C 6 D 6 , 25 °C): δ = 2.10 (t, J = 5.8 Hz, 4 H, NCH 2 ), 2.85–2.92 (q, 4 H, 2 NCH 2 C 6 F 5 ), 3.06 (s, 2 H, PhCH 2 ), 3.78 (br.…”