Formation of a macrocycle from di-chloro-dimethyl-silane and a pyridoxalimine Schiff base ligand.

The reaction of di-chloro-dimethyl-silane with a polydentate Schiff base ligand derived from pyridoxal and 2-ethano-lamine yielded the macrocyclic silicon compound (8E,22E)-4,4,12,18,18,26-hexa-methyl-3,5,17,19-tetra-oxa-8,13,22,27-tetra-aza-4,18-disilatri-cyclo-[22.4.0.010,15]octa-cosa-1(24),8,10,12,14,22,25,27-octa-ene-11,25-diol, C24H36N4O6Si2. The asymmetric unit contains the half macrocycle with an intra-molecular O-H⋯N hydrogen bond between the imine nitro-gen atom and a neighbouring oxygen atom. The crystal structure is dominated by C-H⋯O and C-H⋯π inter-actions, which form a high ordered mol-ecular network.

The heteroscorpionate ligand 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethanol and an easy preparation of its tungsten complex.

The heteroscorpionate ligand 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethanol, C24H26N4O, features in the solid state an intramolecular O-H...N hydrogen bond. A heteroscorpionate tungsten complex, cis-[2,2-bis(3,5-dimethylpyrazolyl)-1,1-diphenylethanolato]chloridodioxidotungsten(VI) tetrahydrofuran monosolvate, [W(C24H25N4O)ClO2]·C4H8O, was prepared by the simple mixing of solutions of the ligand and WOCl4 in tetrahydrofuran. The tungsten complex was isolated after standing for several weeks. The complex exhibits a κ3N,N',O-coordination of the ligand. This simple synthetic procedure allows access to the cis isomer in high yield without additional purification steps. The Hirshfeld surface analysis shows a change of the intermolecular contacts due to the coordination of the WO2Cl unit with the ligand molecule.

Formation of a silicon-containing macrocycle with a pyridoxalimine Schiff base ligand.

The reaction of dichlorodiphenylsilane with a polydentate Schiff base ligand derived from pyridoxal and 2-hydroxyaniline yields the macrocyclic centrosymmetric silicon compound 9,27-dimethyl-3,3,21,21-tetraphenyl-2,4,20,22-tetraoxa-8,13,26,31-tetraaza-3,21-disilapentacyclo[30.4.0.0(6,11).0(14,19).0(24,29)]hexatrideca-1(32),6,8,10,12,14,16,18,24,26,28,30,33,35-tetradecaene-10,28-diol chloroform tetrasolvate, C(52)H(44)N(4)O(6)Si(2) x 4CHCl(3). The asymmetric unit contains half of the macrocycle and two molecules of chloroform, with C-H...O and C-H...N contacts binding the two guests to the host in the crystal structure. This macrocyclic silicon compound represents a promising host for molecular-recognition processes and for the construction of nanostructures.

2,2-Dichloro-1,3-bis(trimethylsilyl)-1,3-diaza-2-silacyclopentane.

In the title compound, C(8)H(22)Cl(2)N(2)Si(3), the central Si atom is tetrahedrally coordinated by two Cl and two N atoms in a molecule that has crystallographically imposed C(2) symmetry. Comparison is made with the isomorphous structure having titanium instead of silicon at the central position in the diazacyclopentane ring [Tinkler, Deeth, Duncalf & McCamley (1996). Chem. Commun. pp. 2623-2624].

4-[(2-Hydroxyethyl)iminomethyl]-5-hydroxymethyl-2-methylpyridin-3-ol.

The title compound, C(10)H(14)N(2)O(3), is a Schiff base which is derived from pyridoxal and represents, therefore, a vitamin B(6)-related compound. Molecules are linked into sheets by a combination of O-H...O and O-H...N hydrogen bonds.