Synthesis and study of triorganostannyl esters of 3-,4- and 3,5-pyridinylimino substituted aminobenzoic acids: Crystal structures of dimorphs of aqua-trimethyltin 3-pyridinyliminobenzoate

Crystal structure of (E)-4-bromo-N-(pyridin-2-ylmethylene)aniline, C12H9BrN2

C12H9BrN2, monoclinic, P21/c (no. 14), a = 19.2197(12) Å, b = 4.8579(3) Å, c = 11.4679(9) Å, β = 106.880(4)°, V = 1024.60(12) Å3, Z = 4, Rgt(F) = 0.0449, wRref(F2) = 0.1257, T = 100(2) K.

Crystal structure of (E)-N-(4-chlorophenyl)-1-(pyridin-2-yl)methanimine, C12H9ClN2

C12H9ClN2, monoclinic, P21/c (no. 14), a = 19.0184(3) Å, b = 4.81220(10) Å, c = 11.3896(2) Å, β = 107.388(1)°, Z = 4, V = 994.75(3) Å3, R gt(F) = 0.0284, wR ref(F 2) = 0.0800, T = 100(2) K.

Crystal structure of (E)-5-benz-yloxy-2-{[(4-nitro-phen-yl)imino]-meth-yl}phenol

In the title compound, C20H16N2O4, the mol-ecule adopts an E conformation about the N=C bond. There is an intra-molecular O-H⋯N hydrogen bond forming an S(6) ring motif. The nitro-benzene and benz-yloxy rings are inclined to the central benzene ring by 4.34 (10) and 27.66 (11)°, respectively, and to one another by 31.40 (12)°. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming zigzag chains along [001]. Within the chains there are C-H⋯π inter-actions present. The chains are linked via π-π inter-actions [inter-centroid distance = 3.7048 (15) Å], forming slabs parallel to the bc plane.

Crystal structure of 4-nitro-N-[(pyridin-2-yl)methyl-idene]aniline

The title compound, C12H9N3O2, adopts an E conformation at the imine double bond. The pyridyl ring makes a dihedral angle of 47.78 (5)° with the benzene ring, indicating the mol-ecule is twisted. In the crystal, mol-ecules are π-π stacked into columns parallel to [100], with an inter-planar separation of 3.8537 (8) Å, corresponding to the length of the a axis. The chains are further linked via weak C-H⋯O and C-H⋯N hydrogen bonds, forming two-dimensional sheets parallel to (010). The sheets interact by van der Waals inter-actions.

Chemistry and applications of organotin(IV) complexes of Schiff bases

Schiff bases are the most widely used versatile ligands, able to coordinate many elements and to stabilize them in various oxidation states. Recently, this class of compounds has been employed as models for biological systems, and in control of stereochemistry in six-coordinate transition metal complexes. Recently, the chemistry of organotin(IV) complexes of Schiff bases has also stemmed from their antitumour, antimicrobial, antinematicidal, anti-insecticidal and anti-inflammatory activities. Furthermore, organotin(IV) complexes of Schiff bases present a wide variety of interesting structural possibilities. Both aliphatic and aromatic Schiff bases in their neutral and deprotonated forms have been used to yield adducts and chelates with variable stoichiometry and different modes of coordination. This critical review (>155 references) focuses upon the chemistry and biological applications of organotin(IV) complexes of Schiff bases reported in the past 15 years. Thermal behavior of these complexes is also discussed.