Synthesis, nuclear magnetic resonance and crystallographic studies of six-co-ordinate bis(bidentate ligand)-dihalogenotin(IV) complexes

Diorganotin(IV) Derivatives of Substituted Benzohydroxamic Acids with High Antitumor Activity

“…[29] Generally, a powerful electron-withdrawing group, such as Cl, increases the strength of the SnÀO bonds. [30,31] n(SnÀCl) for 13 and 14 are at about 310±370 cm À1 and their multiplicity can arise from cis and trans isomers. [29] The mass spectra clearly show the respective molecular ions [M] + and fragments formed upon sequential loss of ligands.…”

Molecular structures of organotin tropolonato complexes with tin coordination numbers 5–7, seen by single‐crystal x‐ray diffraction and solid‐ and solution‐state 119Sn NMR

“…cis-dichlorodi(tropolonato)tin. 15 However, the accuracy of the molecular parameters allows a convincing determination only of its configuration and not of the bond lengths and bond angles owing to the high e.s.d.s (R D 0.115). Taking the small difference in the C-O bond lengths (š0.02 A) in 1, 2a, 2b and3b into account, an assignment to a C O or C-O bond would not be justified.…”

Electronic structures and geometries of six-co-ordinate bis(tropolonate)tin hydrocarbyl and chloride complexes. A combined theoretical ab initio and gas-phase photoelectron spectroscopy study†

“…As a consequence, the cis structure expected is in agreement with other structural characterizations. 14,22 Relevant insights into the electronic factors which govern the geometry of these complexes can be obtained from the metal atomic contributions to MOs involved in the bonding. In particular, a greater, total metal admixture is found in both the n ± (σ Sn᎐O ) and π Sn᎐Cl MOs of SnCl 2 (trop) 2 on passing from the trans to the cis structure (Table 1), hence covalent interactions are favoured in the cis geometry.…”

“…Despite some discrepancies, today it is well accepted that bis-chelate tin() dihalide complexes adopt slightly distorted cis structures. 14 In contrast, dimethyl bischelate complexes may adopt either cis or trans conformations. 14 It has been shown, however, that these molecules are not stereochemically rigid and rapid intramolecular exchange between ligand sites occurs with low energy barriers.…”

“…14 In contrast, dimethyl bischelate complexes may adopt either cis or trans conformations. 14 It has been shown, however, that these molecules are not stereochemically rigid and rapid intramolecular exchange between ligand sites occurs with low energy barriers. 35 In spite of the aforementioned experimental studies, scarce attention has been paid to the details of the related electronic structures and, in particular, to those factors which, ultimately, govern the molecular arrangement.…”