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Pro-ligand 5-[(E)-2-(3-pyridyl)-1-diazenyl]-2hydroxybenzoic acid, H′HL meta , was employed for the synthesis of four organotin(IV) complexes, using suitable tri-and diorganotin (IV) precursors, [nBu 3 Sn(HL meta )] n (1), [Bz 3 Sn(HL meta )] n •C 6 H 5 CH 3 (2), [Ph 3 Sn(HL meta )] 4 •C 6 H 5 CH 3 (3), and {[nBu 2 Sn(L meta )] 2 } n •2nDMSO (4). The coordination behavior of compounds 1−3 in solution was judged from the results of the 119 Sn NMR spectroscopic characterization, while the 119 Sn MAS NMR technique was utilized to probe 4, owing to its low-solubility issue. The solid-state structures of 1−4 were determined from single-crystal X-ray diffraction data. The structural analysis revealed that by changing the Sn-R substituents, the molecular coordination geometries and supramolecular structural motifs in the resulting compounds are widely affected. However, one common feature in the crystal structures of these compounds is a strong tendency for the terminal pyridyl nitrogen to bind with the tin atom of an adjacent complex molecule, which influences the ligand bonding interactions and leads to either macrocycle or polymer formation. In compounds 1−3, the triorganotin moieties are embedded in trigonal− bipyramidal coordination polyhedra arising from the ligand in the monodeprotonated salicylate form, [HL meta ] − , by complexation through the carboxylate group, resulting in 1D coordination polymers with a zigzag-type topology for compounds 1 and 2, and a tetranuclear 44-membered macrocyclic ring structure in the case of 3. The different outcome is a result of the all anti-conformation of the [HL meta ] − ligands in compounds 1 and 2, compared with alternating syn-and anti-conformation of the four ligands in 3, and is without doubt related to the variation of the triorganotin functionality. In compound 4, the tin atoms coordinate to the salicylate group of dianionic [L meta ] 2− by chelate ring formation with both the carboxylate and phenolate groups. The combination of syn-conformation of the ligand and secondary building block formation through 4-membered Sn 2 O 2 rings gives rise to 1D tapes containing 22-membered tetranuclear macrocycles. The case study reported herein showed that heteroditopic pyridyl-carboxylate ligands derived from salicylic acid by diazonium coupling are providing an interesting ligand family for complexation and self-assembly studies with a large number of single main group and transition ions and preformed di-or oligonuclear tectons.

Three novel bicycloazastannoxides, namely, [nBu 2 Sn(L 1 )] (1), [nBu 2 Sn(L 2 )] (2) and [Bz 2 Sn(L 3 )] (3) were synthesized in one pot procedures by reacting diorganotin(IV) precursors with a mixture composed of an α-amino acid with either (E)-2-hydroxy-5-((4-nitrophenyl)diazenyl)benzaldehyde or (E)-2hydroxy-5-(phenyldiazenyl)benzaldehyde. Single-crystal X-ray diffraction analysis reveal that compound 1 is monomeric, compound 2 consists of both a monomer and a dimer, while compound 3 is a coordination polymer for which two modifications 3A and 3B were identified. The 119 Sn NMR chemical shifts [a] Prof.

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The title compound, C 10 H 13 NO 3 ÁH 2 O, is a zwitterion hydrate with the zwitterion comprising a central ammonium group and a carboxylate residue. In the zwitterion, the hydroxybenzene and carboxylate groups are directed to the same side of the molecule and each orientated to place an O atom in a position to form an intramolecular ammonium-N-HÁ Á ÁO hydrogen bond, each closing an S(6) loop. The three-dimensional architecture is stabilized by hydroxy-O-HÁ Á ÁO(carboxylate), water-O-HÁ Á ÁO(carboxylate) and ammonium-N-HÁ Á ÁO(water) hydrogen bonds. Structure descriptionReduced Schiff bases such as the title compound were prepared during an on-going study of the coordination chemistry of organotin carboxylates of Schiff bases derived from amino acids (Basu Baul et al., 2013).The title compound, Fig. 1, features a 2-(OH)C 6 H 4 CH 2 NH 2 + CH 2 CH 2 CO 2 À zwitterion and a water molecule of crystallization. The assignment is confirmed by the equivalence of the C . . . O bond lengths, i.e. C10-O2, O3 are 1.2527 (16) and 1.2496 (16) Å , respectively, and the pattern of hydrogen bonding involving the ammonium cation, as discussed below. The C2-C7-N1-C8-C9 backbone of the zwitterion is planar with a r.m.s. deviation = 0.0121 Å . The hydroxybenzene ring is twisted out of this plane [dihedral angle = 70.07 (8) ] as is the carboxylate group [dihedral angle = 48.26 (12) ]. The terminal residues lie approximately to the same side of the molecule and form a dihedral angle of 34.16 (15) . The somewhat flattened U-shaped conformation places both the hydroxy-O atom and one carboxylate-O atom in proximity to one of the ammonium-N-H atoms