Synthesis of Unsymmetrical Ureas with Coumarin and Thiadiazole Ring Under Microwave Irradiation

Unusual constructions of two Salamo-based copper(II) complexes

wo unusual Cu(II) complexes [{Cu(L¹)}₂] (1) and [Cu₂(L²)] (2), with an asymmetric salamo-type bisoxime ligand H₂L¹ were synthesized and characterized by elemental analyses, UV-Vis, fluorescent spectra, Hirshfeld surface analyses and single-crystal X-ray diffraction analyses. For the complex 1, two Cu(II) ions are penta-coordinate by N₂O₂ donor atoms from the (L¹)^2- unit and one bridged phenol oxygen atom from another (L¹)^2- unit. Complex 1 does not have intermolecular hydrogen bonds, formed an isolated zero dimensional structure. Meanwhile, for the complex 2, an unexpected ligand H₄L² was synthesized by aldol condensation reaction of H₂L¹ and acetone upon coordination, then the new ligand and Cu(II) ions combined, formed a highly symmetrical structure, and two Cu(II) ions of the complex 2 have tetra-coordinate environment. With the help of intermolecular hydrogen bonding CH⋯O interactions, a self-assembled infinite 1D supramolecular structure was formed. Meanwhile, the photophysical spectra and Hirshfeld surface analyses of the complexes 1 and 2 were also measured and discussed.

Unprecedented Fluorescent Dinuclear CoII and ZnII Coordination Compounds with a Symmetric Bis(salamo)-Like Tetraoxime

Two unprecedented homometallic Co^II and Zn^II coordination compounds, [M₂(L)(OCH₃)][M₂(L)(OAc)] (M^II = Co^II (1) and Zn^II (2)), with a novel symmetric bis(salamo)-like tetraoxime ligand H₃L were synthesized and characterized by elemental analyses, infrafred (IR), ultraviolet–visible spectroscopy (UV-Vis), fluorescent spectra and single-crystal X-ray diffraction analyses. The unit cell of the two coordination compounds contains two crystallographically and chemically independent dinuclear coordination compounds. In the two coordination compounds, three metal ions are five-coordinated, formed two square pyramidal and a trigonal bipyramidal geometries, and the other metal ion is a hexacoordinate octahedral configuration. In addition, the coordination compound 1 forms a 3D supramolecular structure, and the coordination compound 2 forms a 0D dimer structure by the inter-molecular hydrogen bond interactions. Meanwhile, the fluorescence spectra of the coordination compounds 1 and 2 were also measured and discussed.

Unprecedented Hexanuclear Cobalt(II) Nonsymmetrical Salamo-Based Coordination Compound: Synthesis, Crystal Structure, and Photophysical Properties

A novel hexanuclear Co(II) coordination compound with a nonsymmetrical Salamo-type bisoxime ligandH4L, namely [{Co3(HL)(MeO)(MeOH)2(OAc)2}2]·2MeOH, was prepared and characterized by elemental analyses, UV–vis, IR and fluorescence spectra, and X-ray single-crystal diffraction analysis. Each Co(II) is hexacoordinated, and possesses a distorted CoO6 or CoO4N2 octahedrons. The Co(II) coordination compound possesses a self-assembled infinite 2D supramolecular structure with the help of the intermolecular C–H···O interactions. Meanwhile, the photophysical properties of the Co(II) coordination compound were studied.

A facile one pot route for the synthesis of imide tethered peptidomimetics

A simple and efficient method for the synthesis of N,N’-orthogonally protected imide tethered peptidomimetics is presented. The imide peptidomimetics were synthesized by coupling the in situ generated selenocarboxylate of N^α-protected amino acids with N^α-protected amino acid azides in good yields.

Synthesis of Styryl Substituted Semicarbazides under Microwave Irradiation

A series of styryl substituted semicarbazides were synthesised by reaction of trans-styryl isocyanate, prepared by Curtius rearrangement of cinnamoyl azide, with acid hydrazides under microwave irradiation using a one-pot procedure. The effects of microwave irradiation in promoting the condensation of trans-styryl isocyanate with hydrazides were investigated alongside a conventional heating method (oil bath at 120 °C). When compared with classical methods, microwave irradiation has the advantages of mild conditions, easy handling, and high yields. The products have been characterised by analytical and spectral (IR and 1H NMR) data.