Anion- and Solvent-Directed Assembly in Silver Bis(thioimidazolyl)methane Chemistry and the Silver−Sulfur Interaction

Synthesis, Structure, Biological Activity, and Luminescence Properties of a "Butterfly"-Type Silver Cluster with 3-Benzyl-4-phenyl-1,2,4-triazol-5-thiol

A new silver(I) cluster [Ag8L4(Py)(Pype)]·4Py·11H2O (I) with 3-benzyl-4-phenyl-1,2,4-triazol-5-thiol (L) was synthesized via the direct reaction of AgNO3 and L in MeOH, followed by recrystallization from a pyridine-piperidine mixture. The compound I was isolated in a monocrystal form and its crystal structure was determined via single crystal X-ray diffraction. The complex forms a "butterfly" cluster with triazol-5-thioles. The purity of the silver complex and its stability in the solution was confirmed via NMR analysis. Excitation and emission of the free ligand and its silver complex were studied at room temperature for solid samples. The in vitro biological activity of the free ligand and its complex was studied in relation to the non-pathogenic Mycolicibacterium smegmatis strain. Complexation of the free ligand with silver increases the biological activity of the former by almost twenty times. For the newly obtained silver cluster, a bactericidal effect was established.

Simple synthesis of novel magnetic silver polymer nanocomposites with a good separation capacity and intrinsic antibacterial activities with high performance

Two new coordination polymers namely, [(AgCN)4LS]n (1) and [(AgCN)3LN]n (2), were successfully synthesized by the reaction of AgNO3 and cyanide as a co-anion with LS[1,1'-(hexane-1,4-diyl)bis(3-methylimidazoline-2-thione] and LN[1,1,3,3-tetrakis(3,5-dimethyl-1-pyrazole)propane] ligands in order to use them for the preparation of magnetic nanocomposites with MnFe2O4 nanoparticles by an efficient and facile method. They were then well characterized via numerous techniques, including elemental analysis, FT-IR spectroscopy, TGA, PXRD, SEM, TEM, EDX, VSM, BET, ICP, and single-crystal X-ray diffraction. The considered polymers and their magnetic nanocomposites with nearly the same antibacterial activity demonstrated a highly inhibitive effect on the growth of Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacteria. By considering the simple separation and recyclable characters of the magnetic nanocomposites, these materials are suitable to be used in biological applications.

The exceptionally high moisture responsiveness of a new conductive-coordination-polymer based chemiresistive sensor

A new conductive 3D coordination polymer with reversible coordination bonds and exceptionally high moisture responsiveness was reported as a chemiresistive humidity sensor.

Involvement of various anions in tuning the structure of silver(i) coordination polymers based on a S-donor ligand: syntheses, crystal structure and uptake properties

Ag(i) coordination polymers based on a S-donor ligand containing of various anions were synthesized and characterized. Also, the absorption potential of the polymers was examined by the NH3 and H2S gases.

Synthesis and dye adsorption studies of the {dibromo(1,1′-(1,2-ethanediyl)bis(3-methyl-imidazole-2-thione)dicopper(i)}n polymer and its conversion to CuO nanospheres for photocatalytic and antibacterial applications

A new copper polymer was used as a dye adsorbent and CuO precursor. The CuO nanospheres showed good performances for photocatalytic and antibacterial applications.

N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry

N-Heterocyclic carbenes (NHC) are nowadays ubiquitous and indispensable in many research fields, and it is not possible to imagine modern transition metal and main group element chemistry without the plethora of available NHCs with tailor-made electronic and steric properties. While their suitability to act as strong ligands toward transition metals has led to numerous applications of NHC complexes in homogeneous catalysis, their strong σ-donating and adaptable π-accepting abilities have also contributed to an impressive vitalization of main group chemistry with the isolation and characterization of NHC adducts of almost any element. Formally, NHC coordination to Lewis acids affords a transfer of nucleophilicity from the carbene carbon atom to the attached exocyclic moiety, and low-valent and low-coordinate adducts of the p-block elements with available lone pairs and/or polarized carbon-element π-bonds are able to act themselves as Lewis basic donor ligands toward transition metals. Accordingly, the availability of a large number of novel NHC adducts has not only produced new varieties of already existing ligand classes but has also allowed establishment of numerous complexes with unusual and often unprecedented element-metal bonds. This review aims at summarizing this development comprehensively and covers the usage of N-heterocyclic carbene adducts of the p-block elements as ligands in transition metal chemistry.

Anion- and Solvent-Induced Assembly and Reversible Structural Transformation of d(10)-Metal Coordination Architectures Containing N-(4-(4-Aminophenyloxy)phenyl)isonicotinamide

We set out studies on anion- and solvent-induced assembly based on the ligand N-(4-(4-aminophenyloxy)phenyl)isonicotinamide (papoa), which is synthesized to show a bent and flexible backbone. Reactions of papoa with ZnX2 (X=Cl, Br, and I) gave the dinuclear macrocycles ([ZnX2 (papoa)]2 ; X=Cl (1 a), Br (2 a), I (3)), the structure of which was determined by X-ray diffraction. Notably, the less bulky Cl and Br compounds afforded the coordinated imine in acetone (i.e., [ZnX2 (papoi)]2 , papoi=N-(4-(4-(propan-2-ylideneamino)phenoxy)phenyl)isonicotinamide; X=Cl (1 b), Br (2 b)), whereas the iodine one only gave the coordinated amine compound 3 under the same reaction condition. In fact, the coordinated imine can return to the amine analogue upon exposure to air or in DMSO, which has been monitored by (1)H NMR spectroscopy and powder X-ray diffraction. Both the dinuclear [Zn(papoa)(NO3)2]2 (4 a) and the 1D [Zn(papoa)2(NO3)2]n (4 b) were formed from the reaction of Zn(NO3)2 and papoa in mixed solvents with acetone and acetonitrile, respectively. In addition, Cd(ClO4)2 can react with papoa to give the 1D framework {[Cd(papoa)2 (CH3CN)2](ClO4)2}n (5 a) and the 2D framework [Cd(papoa)2 (ClO4)2]n (5 b), depending on the solvent used, that is, MeOH and CH3CN, respectively. Importantly, the 1D framework with axially coordinated CH3 CN molecules and the 2D framework with axially coordinated ClO4(-) ions can be interconverted by heating and grinding in the presence of CH3CN, respectively. Such a reversible structural transformation process was proven by PXRD studies.

Dinuclear copper(i) complexes with N-heterocyclic thione and selone ligands: synthesis, characterization, and electrochemical studies

We report dinuclear copper(i) complexes with a variety of monodentate and bidentate thione- and selone-containing ligands. Cu(ii/i) potentials were tuned in a 470 mV range depending on the chalcogenone ligands.