The crystal and mol-ecular structures of two tri-phenyl-tin di-thio-carbamate compounds,
. Sn(C
H
)
(C
H
NS
), (I), and Sn(C
H
)
(C
H
NS
), (II), are described. The di-thio-carbamate ligand in each ...mol-ecule coordinates in an asymmetric fashion resulting in heavily distorted tetra-hedral C
S coordin-ation geometries for the Sn atoms, with the distortions traced to the close approach of the non-coordinating thione-S atom. The mol-ecular packing in both compounds features C-H⋯π(Sn-phen-yl) inter-actions. In (I), the donors are Sn-phenyl-C-H groups leading to centrosymmetric aggregates, while in (II), the donors are both Sn-phenyl-C-H and methyl-C-H groups leading to supra-molecular chains propagating along the
axis. The identified aggregates assemble into their respective crystals with no directional inter-actions between them. An analysis of the Hirshfeld surfaces show distinctive patterns, but an overwhelming predominance (>99% in each case) of H⋯H, C⋯H/H⋯C and S⋯H/H⋯S contacts on the respective Hirshfeld surface.
A novel nano-cauliflower-shaped lead(II) metal–organic coordination polymer, Pb(μ-2-pinh)N
3
H
2
O
n
(
1
), was synthesized using an ultrasonic method. The nanostructure was characterized by scanning ...electron microscopy (SEM), X-ray powder diffraction, IR spectroscopy, elemental analysis, and thermal analysis. The compound was structurally characterized by single-crystal X-ray diffraction. The coordination compound takes the form of a zig-zag one-dimensional polymer in solid state. The coordination number of the lead(II) ions is six (PbN
4
O
2
) with three nitrogen atoms and one oxygen atom from two linker organic ligands, as well as one oxygen from coordinated water and one nitrogen atom from terminal coordinated azide anion. It has a stereo-chemically active lone electron pair, and the coordination sphere is hemidirected. The zig-zag 1D chains interact with neighbouring chains through weak interactions, creating a 3D supramolecular metal–organic framework. Lead oxide nanoparticles were obtained by thermolysis of the new nano coordination compound at 180 °C with oleic acid as a surfactant. The morphology and size were further studied using SEM. Natural bond orbital analyses demonstrate the electronic properties of the lead centre and other atoms.
C28H24Cl4Sn, orthorhombic, Fdd2 (no. 43), a = 22.01600(10) Å, b = 20.79690(10) Å, c = 11.15230(10) Å, V = 5106.24(6) Å3, Z = 8, Rgt(F) = 0.0134, wRref(F2) = 0.0370, T = 100(2) K.
The title compound, C13H19NO8, is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C-C bond; the Cm-Ca-Ca-Cme torsion angle is 38.26 (15)° m = ...methyl-carboxyl-ate, a = acet-yloxy and me = methyl-ene. While the N-bound ethyl-carboxyl-ate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supra-molecular double-layers are formed by weak methyl- and methyl-ene-C-H⋯O(carbon-yl) inter-actions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional inter-actions between them. The Hirshfeld surface is dominated by H⋯H (55.7%) and H⋯C/C⋯H (37.0%) contacts; H⋯H contacts are noted in the inter-double-layer region. The inter-action energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal.
The title compound comprises a neutral molecule, its zwitterionic tautomer whereby the N-bound proton of the central ring is now resident on the pendant ring, and a water molecule of ...crystallization. Conventional hydrogen bonding leads to supramolecular layers in the crystal.
The title compound, 2C
14
H
14
N
4
O·H
2
O, comprises a neutral molecule containing a central pyrazol-3-one ring flanked by an N-bound phenyl group and a C-bound 5-methyl-1
H
-pyrazol-3-yl group (at positions adjacent to the carbonyl substituent), its zwitterionic tautomer, whereby the N-bound proton of the central ring is now resident on the pendant ring, and a water molecule of crystallization. Besides systematic variations in geometric parameters, the two independent organic molecules have broadly similar conformations, as seen in the dihedral angle between the five-membered rings 9.72 (9)° for the neutral molecule and 3.32 (9)° for the zwitterionic tautomer and in the dihedral angles between the central and pendant five-membered rings 28.19 (8) and 20.96 (8)° (neutral molecule); 11.33 (9) and 11.81 (9)°. In the crystal, pyrazolyl-N—H⋯O(carbonyl) and pyrazolium-N—H⋯N(pyrazolyl) hydrogen bonds between the independent organic molecules give rise to non-symmetric nine-membered {⋯HNNH⋯NC
3
O} and {⋯HNN⋯HNC
3
O} synthons, which differ in the positions of the N-bound H atoms. These aggregates are connected into a supramolecular layer in the
bc
plane by water-O—H⋯N(pyrazolide), water-O—H⋯O(carbonyl) and pyrazolyl-N—H⋯O(water) hydrogen bonding. The layers are linked into a three-dimensional architecture by methyl-C—H⋯π(phenyl) interactions. The different interactions, in particular the weaker contacts, formed by the organic molecules are clearly evident in the calculated Hirshfeld surfaces, and the calculated electrostatic potentials differentiate the tautomers.
An approach to highly functionalized tetrahydrofuran derivatives based upon a novel Oxa-Michael/Michael dimerization of cis-γ-hydroxyenones is presented. The reaction begins with either 1,2-dioxines ...or trans-γ-hydroxyenones and proceeds by addition of one molecule of trans-γ-hydroxyenone to another molecule of cis- or trans-γ-hydroxyenone catalyzed by an alkoxide or hydroxide base. Subsequent intramolecular Michael addition of the keto−enolate gives the observed tetrahydrofurans. Substitution at both the 2- and 4-positions of the γ-hydroxyenone is tolerated; however, for 4-substituted γ-hydroxyenones, selectivity issues arise due to the possibility of heterochiral or homochiral dimerizations. The major products were those with all contiguous groups trans.
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