Synthesis, Molecular Structure, and Solution Stereochemistry of Hypercoordinated Bis(3-(dimethylamino)propyl)tin Compounds. Dissociative (Nonregular) and Nondissociative (Regular) Isomerization Pathways

Abstract

The syntheses of [Me2N(CH2)3]2Sn(EAr)2 (1, E = O, Ar = C6H5; 2, E = O, Ar = p-t-BuC6H4; 3, E = O, Ar = p-NO2C6H4; 4, E = O, Ar = o-FC6H4; 7, E = S, Ar = C6H5), [Me2N(CH2)3]2Sn(o-O2C6H3R-3) (5, R = H; 6, R = OCH3), and {[Me2N(CH2)3]2SnPh}+I- (8) are reported. X-ray diffraction analyses reveal distorted-octahedral geometries for the tin atoms in compounds 1−7 with, except for the stannaindane derivative 5, the carbon atoms in mutually trans positions, while the nitrogen and oxygen atoms are cis. In compound 5, the carbon atoms are cis, whereas the nitrogen atoms are trans. Compound 8, in contrast, is ionic and consists of an intramolecularly pentacoordinated triorganotin cation and an iodide anion. Variable-temperature 1H, 13C, and 119Sn NMR investigations reveal the compounds to have similar structures in solution. The coalescence phenomena observed in the 1H and 13C NMR spectra are explained both in terms of Sn−O bond cleavage (1−4) and chirality inversion through a sequence of five intramolecular Berry-type pseudorotations (1−4, 8), interconverting the enantiomers with propeller-like geometry. The dynamic behavior in solution of the stannaindane derivatives 5 and 6 and of the thiophenolate derivative 7 is interpreted in terms of intramolecular Sn−N bond dissociation.

Catalytic Conversion of Carbohydrates into 5‐Hydroxymethylfurfural by Germanium(IV) Chloride in Ionic Liquids

“…The ability of heavier main-group elements to accommodate more than eight electrons in their valence shells, thus forming so-called hypervalent or hypercoordinate compounds, is well established. [20] The cations of Group 14 elements can be stabilized Figure 7. The results of glucose dehydration to HMF catalyzed by GeCl 4 in different solvents for 75 min.…”

Structure of azo dye organotin(IV) compounds containing a C,N‐chelating ligand, part II, and their in vitro antifungal activity

“…C(6 )), 137.7 (C(7 )), 118.1 (C(9 )), 130.4 (C(10 )), 129.6 (C(12 )), 141.9 (C(11 )), 127.6 (C(5), 3 J( 119 Sn, 13 C) = 56.9 Hz), 137.8 (C(6), 2 J( 119 Sn, 13 C) = 31.5 Hz), 33.9 (C(13 )), 31.3 (C(14 ) …”

“…1), which are also involved in many industrial applications. 8 -11 Some of the compounds can occur in two tautomeric forms (3)(4)(5)(6), and there is also the theoretical possibility of increasing the tin coordination number via the coordination of the dye intrinsic donor atoms.…”

Structure of azo dye organotin(IV) compounds containing a C,N‐chelating ligand

“…6,7 We have previously reported on the evaluation of intramolecular Sn-N interactions in these types of compound using NMR spectra parameters. 8,9 Organotin(IV) compounds have also been extensively studied and screened in vitro and in vivo for antitumour activity.…”