Rare proximity enforced copper hydrogen interactions in copper(i)-chalcogenones

Copper(I) chalcogenones with rare Cu⋯H–C(sp3) hydrogen bonding interactions have been reported. The copper(I) bis(benzimidazole-2-chalcogenone) complexes [Cu(L1)4]+BF4− (1) and [Cu(L2)4]+BF4− (2) (L1 = bis(1-isopropyl-benzimidazole-2-selone)-3-ethyl; L2 = bis(1-isopropyl-benzimidazole-2-thione)-3-ethyl) have been synthesized and characterized. Both complexes possess distorted tetrahedral geometry with a semi-trans arrangement of the benzimidazole-chalcogenone ligands around the Cu(I) center. The structures of 1 and 2 reveal homoleptic coordination with the Cu(I) center with the (sp3)C–H groups of the ethylene linker directed towards the Cu(I) center to maximize the rare proximity-enforced intramolecular Cu⋯H–C interactions. The Cu⋯H–C interactions are found to have a hydrogen bonding nature in the crystalline state, as these interactions are absent in the solution state

Rhenium(I)-based Double-heterostranded Helicates

Rhenium(I)-based supramolecular coordination complexes were obtained using Re2(CO)10, (2-hydroxyphenyl)benzimidazole-derived bis-chelating N?O donors and a benzimidazolyl-derived ditopic monodentate N-donor possessing Troger's base spacer in a one-pot approach

Luminescent Behavior of Liquid–Crystalline Gold(I) Complexes Bearing a Carbazole Moiety: Effects of Substituent Bulkiness

Organometallic materials that exhibit white luminescence in condensed phases are of considerable interest for lighting and display applications. Herein, new carbazole-based Au(I) complexes containing an isocyanide group and a long pentyl chain were synthesized. The complex with an unsubstituted carbazole moiety exhibited a white emission at room temperature as well as nematic liquid crystalline behavior. Color tunability from white to blue was achieved when bulkier substituents were introduced at the 3 and 6 positions of the carbazole moiety. Fur-thermore, all complexes possessed long phosphorescence lifetimes in the crystal state. The pro-posed design framework provides new opportunities for practical applications using luminescent organometallic molecules. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Mechanically tunable photo-cross-linkable bioinks for osteogenic differentiation of MSCs in 3D bioprinted constructs

3D bioprinting technique renders a plausible solution to tissue engineering applications, mainly bone tissue regeneration, which could provide the microenvironment with desired physical, chemical, and mechanical properties. However, the mechanical and structural stability of current natural polymers is a critical issue in the fabrication of bone tissue-engineered scaffolds. To overcome these issues, we have developed 3D bioprintable semi-synthetic polymers derived from natural (sodium alginate, A) and synthetic (polyethylene glycol, PEG) biopolymers. In order to enhance the cross-linking properties and biocompatibility, we have functionalized these polymers with acrylate and methacrylate chemical moieties. These selected combination of natural and synthetic polymers improved the mechanical strength due to the synergistic effect of covalent as well as ionic bond formation in the hydrogel system, which is evident from the tested tensile data. Further, the feasibility of 3D bioprinting of acrylate and methacrylate functionalized PEG and hydrogels have been tested for the biocompatibility of the fabricated structures with human umbilical cord mesenchymal stem cells (UMSCs). Further, these bioprinted scaffolds were investigated for osteogenic differentiation of UMSCs in two types of culture conditions: namely, i) with osteoinduction media (with OIM), ii) without osteoinduction media (w/o OIM). We have examined the osteoinductivity of scaffolds with the activity of alkaline phosphatase (ALP) content, and significant changes in the ALP activity was observed with the stiffness of developed materials. The extent osteogenic differentiation was observed by alizarin red staining and reverse transcription PCR analysis. Elevated levels of ALP, RUNX2 and COL1 gene expression has been observed in without OIM samples on week 1 and week 3. Further, our study showed that the synthesized alginate methacrylate (AMA) without osteoinduction supplement with young's modulus of 0.34 MPa has a significant difference in ALP quantity and gene expression over the other reported literature. Thus, this work plays a pivotal role in the development of 3D bioprintable and photo-cross-linkable hydrogels in osteogenic differentiation of mesenchymal stem cells. © 2021 Elsevier B.V

Chalcogen Bonding Induced Tetraselenides from Twisted Diselenides

The first sterically controlled oxidation of mesoionic selone using copper(II) salt was demonstrated. The present methodology gave access to a rare tetraselenide from dimerized diselenides through chalcogen bonding (ChB). Besides, a similar approach with sterically less crowded mesoionic triazole selone, 1-(2-mesitylene)-3-methyl-4-phenyltriazolin-5-selone, gave the classic diselenide salt. In the solid state, these new selenide salts demonstrate a unique structural aggregation with unusual bonding features such as Se···O and Se···F interactions

Antimony(III) Halide‐Assisted Stereospecific Coordination of Thione

The antimony halide-aided stereospecific coordination of a cyclic thiourea-type of ligand is observed for the first time. The antimony(III) imidazole thione complexes syn-[(L1)SbCl3] (syn-1) and anti-[(L1)SbBr3] (anti-2) have been synthesized in very good yield by the reaction between the spatially defined steric impact ligand [(IPaul)S] (L1) ([(IPaul)S]=1,3-bis(2,4-methyl-6-diphenyl phenyl)imidazole thione) and corresponding antimony halide. The stereoselective formation of complexes syn-1 and anti-2 has been confirmed by both NMR and single-crystal X-ray diffraction studies. Interestingly the stereospecific nature of syn-1 and anti-2 remains intact in solution. Furthermore, the thermal stability of antimony(III) imidazole thione complexes were examined by TGA analysis

Highly Active Cu(II) Diimine Catalyzed Click Reactions: A Mild Yet Fast Approach to Carbazole Substituted 1,2,3-Triazoles

Two mild Cu(II) diimine catalyzed click reactions have been reported to be efficient, robust, and additive-free one-pot procedures to isolate carbazole decorated 1,2,3-triazoles with high regioselectivity. The Cu(II) diimine complex [(L)Cu(OAc)2(OH2)], where L = N-(2-pyridinylmethylene)-2,6-dibenzhydryl-4-methoxylamine, was synthesized and characterized. In the first method, the click reactions were demonstrated between 9-(2-propynyl)-carbazole and aryl azide using catalyst 1 at room temperature in water. In the second approach, the fast and convenient procedures to prepare carbazole decorated 1,2,3-triazoles were reported through the mechanical grinding method, which enabled the isolation of carbazole decorated 1,2,3-triazoles within 6:32 min. Besides, both the catalytic protocols were demonstrated without the addition of either external reductant or base. The structural details of carbazole decorated 1,2,3-triazoles were elucidated using single-crystal X-ray diffraction and NMR techniques. Graphical Abstract: Two mild Cu(II) diimine catalyzed click reactions have been reported to be efficient, robust, and additive-free one-pot procedures to isolate carbazole decorated 1,2,3-triazole derivatives with high regioselectivity. [Figure not available: see fulltext.]. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature

A novel dimeric copper salicylate with an undissociated COOH group: synthesis and crystal structure of [Cu<SUB>2</SUB>(HSal)(Sal)(2,2'-bpy)<SUB>2</SUB>](ClO<SUB>4</SUB>)

A dinuclear copper salicylate [Cu2(HSal)(Sal)(2,2'-bpy)2](ClO4) (1) (H2Sal = salicylic acid) has been synthesized and characterized with the aid of elemental analysis and infrared, ultraviolet and fluorescence spectroscopic studies. The molecular structure of 1, determined by single-crystal X-ray diffraction studies, shows the presence of incompletely deprotonated salicylate ligands in the complex. Hydrogen bonding interactions and &#960;-&#960; aromatic stacking lead to the formation of 2D polymeric structure in the solid state