A sandwich-type cluster containing Ge@Pd3 planar fragment flanked by aromatic nonagermanide caps

Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)]4{(Ge9)2[η6-Ge(PdPPh3)3]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd3. The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp2-Ge@(PdPPh3)3 trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The chemical bonding pattern of the planar fragment consists of three 2c-2e Pd-Ge σ-bonds attaching Pd atoms to the core Ge atom, while the binding between the planar fragment and the aromatic Ge9 ligands is provided by six 2c-2e Pd-Ge σ-bonds and two delocalized 4c-2e σ-bonds. The synthesized cluster represents a rare example of a sandwich compound with the heteroatomic metal planar fragment and inorganic aromatic capping ligands.

Methyl 1-allyl-4-hydroxy-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate

There are two independent molecules in the asymmetric unit of the title compound, C13H13NO5S, in both of which the ester substituent is nearly coplanar [C—C—C—O torsion angles = 2.7 (7) and −0.8 (7)°] with the planar fragment of the bicycle due to the formation of a strong O—H...O intramolecular hydrogen bond. The vinyl group at the ring N atom is approximately orthogonal to the heterocyclic mean plane [C—N—C—C torsion angles = 103.1 (6) and 98.2 (5)°]. The refinement was performed on a two-component, non-merohedrally twinned crystal [population ratio = 0.483 (3):0.517 (3).

3,5-Bis[4-(diethylamino)benzylidene]-1-methyl-4-piperidone and 3,5-bis[4-(diethylamino)cinnamylidene]-1-methyl-4-piperidone: prospective biophotonic materials

The structures of 3,5-bis[4-(diethylamino)benzylidene]-1-methyl-4-piperidone, C28H37N3O, (I), and 3,5-bis[4-(diethylamino)cinnamylidene]-1-methyl-4-piperidone, C32H41N3O, (II), have been characterized. Because of conjugation between donor and acceptor parts, the central heterocycles (including the carbonyl group) in (I) and (II) are flattened and exhibit a `sofa' conformation, with a deviation of the N atom from the planar fragment. The dihedral angles between the planar part of the heterocycle and the two almost flat fragments that include a phenyl ring and bridging atoms are 23.2 (1) and 11.2 (1)° in (I), and 11.8 (1) and 8.7 (2)° in (II). One- and two-photon absorption of light and the fluorescence of (I) and (II) have also been characterized.

Crystal Structure of the Di-bromo-bis(2-dimethylaminoethanolato)(dimethylsulfoxide)-copper(II)-lead(II) Dimer Obtained by Direct Synthesis

A heterotetranuclear CuIIPbII complex containing 2-dimethylaminoethanol has been synthesized, using copper powder and PbBn2 as starting materials, and characterized by X-ray crystallography. The crystal is composed of centrosymmetric molecules [CuPbBr2{(CH3)2NCH2CH2O}2dmso]2. The central strictly planar fragment is a Pb2O2 parallelogram completed by bridging oxygen atoms of chelating 2-dimethylaminoethoxo groups. The Pb atom forms four quite short bonds with oxygen atoms of the three 2-dimethylaminoethoxo groups and of the dmso molecule and assumes a six-coordinate structure also involving two bromine atoms. The two oxygen and two nitrogen atoms of two 2-dimethylaminoethoxo groups form the copper coordination environment, which possesses a somewhat distorted square planar geometry.