A Comparative Assessment of the Effect of the Lewis Acidity of the Central Tin Atom on Intramolecular Coordination of (3‐Methoxypropyl)stannanes

Abstract

The recently studied set of (3‐methoxypropyl)stannanes of general formula RxSnCl4–x [R = (CH2)3OCH3, x = 4 (1), x = 3 (2), x = 2 (3) and x = 1 (4)] is extended with two new sets of (3‐methoxypropyl)stannanes of general formula RPh3–xSnClx [x = 0 (5), x = 1 (6) and x = 2 (7)] and RSn(S2CNEt2)3–xClx [x = 0 (8), x = 1 (9) and x = 2 (10)]. The molecular structures of 6, 7, 9 and 10 in the solid state were determined by X‐ray diffraction. In compounds 6 and 7, the 3‐methoxypropyl ligand forms a C,O‐chelate and the tin atom is coordinated as a distorted trigonal bipyramid with the oxygen and one chlorine atom in the axial positions. Compounds 9 and 10 are hexacoordinate with a distorted octahedral ligand arrangement. While the 3‐methoxypropyl ligand in 10 also forms a C,O‐chelate, the oxygen atom in 9 is not coordinated to the central tin atom. The structures in a non‐coordinating (CDCl3) and a coordinating solvent ([D6]DMSO) were studied by multinuclear 1H, 13C and 119Sn NMR spectroscopy. It is proposed that the structures found in the solid state are retained upon dissolution in CDCl3. Compounds 5, 8 and 9 also preserve their structures in [D6]DMSO. On the other hand, an equilibrium, in which one or more molecules of solvent enter the coordination sphere of the central tin atom and cleave the oxastannacycle, is established in [D6]DMSO solutions of 6, 7 and 10. A comparison of the J 1H, 119Sn coupling constants obtained from 1D 1H,119Sn HMQC and 2D 1H,119Sn J‐HMBC spectra and the J 13C, 119Sn coupling constants derived from conventional 1D 13C NMR spectra shows that the best indicator of the O→Sn donor–acceptor interaction in 3‐methoxypropylstannanes is the 3J 13C, 119Sn value. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Crystal structure of n-butyl-chlorido-bis[N-sec-butyl,N-n-propyl-carbamodithioato κ 2 S,S′]-tin(IV), C20H41ClN2S4Sn

“…In continuation of ongoing studies of the structural chemistry of molecules of the general formula RSn(S 2 CNR′R′′) 2 Cl, R, R′, R′′ = alkyl and/or aryl [2], the structure of the R = n-butyl, R′ = n-propyl and R′′ = secbutyl derivative, has been investigated. The structural motif adopted by the title molecule is common to all other molecules having this generic formula [2][3][4][5][6][7][8][9][10][11][12]. Thus, the Sn atom exists within a C, Cl, S4 donor set that describes a distorted octahedral geometry, being coordinated by n-butyl- …”

Application of computational modeling to analyze reactive organotin(IV) species

“…Conditions determinable by a reliable COM, such as solvents and temperature, are likely influences on which of two conformations are favored: linear monodentate or cyclic bidentate. The cyclic conformation has a C-O bidentate chelating ligand, which forms an intramolecular partial scorpionate-like bond with the Sn(IV) atom [12,40,45]. A reliable COT that may distinguish between the properties of the two conformations would benefit this research.…”

“…Also, thio 0 has no chlorine atoms to perform an electron withdrawing function. Hence, thio 3 should form the weakest of the S-Sn hypercoordination bonds in the series and set control values [40].…”

“…4 and 5) [17,40]. Although thio 3 has not yet been examined experimentally, based on the present COT research, thio 3 is expected to follow the trend set by thio 1 and thio 2 regarding an expectation of increased hypercoordination bond strength.…”

Structural systematics of RSn(S 2CN R′ R″) 2Cl compounds

“…2, exhibited homogeneity in their molecular structures with octahedral coordination geometries defined by chelating dithiocarbamate ligands and with mutually cis tin-bound organic and chloride substituents [21][22][23][24][25][26][27][28][29][30]. It is noted that all these examples contain symmetrically substituted dithiocarbamates ligands, i.e.…”