Syntheses, IR spectra, thermal properties and crystal structures of novel cyano-bridged polymeric complexes of zincII and cadmiumII with tetracyanoplatinateII

Highly emissive polymorphs of anhydrous cadmium tetracyanoplatinate and their solvated coordination networks

Two anhydrous polymorphs of cadmium cyanoplatinate Cd[Pt(CN)₄] coordination polymers have been synthesized and thermally, spectroscopically, and structurally characterized. α-Cd[Pt(CN)₄] and β-Cd[Pt(CN)₄] are densely packed, highly emissive 3-D solids, with quantum yields of 0.85 (λ_em = 520 nm) and 0.79 (λ_em = 448 nm) respectively. Their mutual hydrate, Cd(H₂O)[Pt(CN)₄]·2H₂O, forms a complex 3-D coordination polymer with Cd-O-Cd bridges and Pt-Pt interactions. Additionally, exposure of solid α-Cd[Pt(CN)₄] and β-Cd[Pt(CN)₄] to several solvent vapours results in the formation of 2-D cyanometallate sheets of the adduct compounds CdL₂[Pt(CN)₄] (L = DMSO, DMF, and pyridine). Cd(pyridine)₂[Pt(CN)₄] shows a significantly lower quantum yield (0.32) in comparison to the parent Cd[Pt(CN)₄] coordination polymers. Upon heating CdL₂[Pt(CN)₄] preferentially forms the kinetic product α-Cd[Pt(CN)₄].

Mixed-Valent Cyanoplatinates Featuring Neptunyl-Neptunyl Cation-Cation Interactions

The tetracyanoplatinate ligand was employed in synthesizing the first neptunyl cyanoplatinate complexes. Results indicate in situ oxidation of Pt(II) by Np(V/VI) to form mixed-valent Pt-Pt stacked columnar chains linked by cation-cation interaction induced chains of Np(V) polyhedra into a two-dimensional sheet structure. The Pt-Pt stacking distances of 3.04-3.05 Å are the longest reported columnar platinophilic interactions among mixed-valent tetracyanoplatinate structures. These complexes further illustrate the marked chemical differences and structural diversity of solid-state Np(V) coordination complexes with regard to Np(VI) and U(VI).

A cyanide-bridged heterometallic coordination polymer constructed from square-planar [Ni(CN)4]2−: synthesis, crystal structure, thermal decomposition, electron paramagnetic resonance (EPR) spectrum and magnetic properties

Square-planar complexes are commonly formed by transition metal ions having ad8electron configuration. Planar cyanometallate anions have been used extensively as design elements in supramolecular coordination systems. In particular, square-planar tetracyanometallate(II) ions,i.e.[M(CN)4]2−(MII= Ni, Pd or Pt), are used as good building blocks for bimetallic Hofmann-type assemblies and their analogues. Square-planar tetracyanonickellate(II) complexes have been extensively developed withN-donor groups as additional co-ligands, but studies of these systems usingO-donor ligands are scarce. A new cyanide-bridged CuII–NiIIheterometallic compound, poly[[diaquatetra-μ2-cyanido-κ8C:N-nickel(II)copper(II)] monohydrate], {[CuIINiII(CN)4(H2O)2]·H2O}n, has been synthesized and characterized by X-ray single-crystal diffraction analyses, vibrational spectroscopy (FT–IR), thermal analysis, electron paramagnetic resonance (EPR) and magnetic moment measurements. The structural analysis revealed that it has a two-dimensional grid-like structure built up of cationic [Cu(H2O)2]2+and anionic [Ni(CN)4]2−units connected through bridging cyanide ligands. The overall three-dimensional supramolecular network is expanded by a combination of interlayer O—H...N and intralayer O—H...O hydrogen-bond interactions. The first decomposition reactions take place at 335 K under a static air atmosphere, which illustrates the existence of guest water molecules in the interlayer spaces. The electron paramagnetic resonance (EPR) spectrum confirms that the CuIIcation has an axial coordination symmetry and that the unpaired electrons occupy thed_{{{{x}^2}-y^2} orbital. In addition, magnetic investigations showed that antiferromagnetic interactions exist in the CuIIatoms through the diamagnetic [Ni(CN)4]2−ion.

Synthesis, spectroscopic, thermal and structural properties of [M(3-aminopyridine)2Ni(μ-CN)2(CN)2]n (M(II)=Co and Cu) heteropolynuclear cyano-bridged complexes

Two novel cyano-bridged heteropolynuclear complexes, [Co(3-aminopyridine)2Ni(μ-CN)2(CN)2]n and [Cu(3-aminopyridine)2Ni(μ-CN)2(CN)2]n have been synthesized and characterized by elemental, thermal, FT-IR and FT-Raman spectroscopies. The structures of complexes have been determined by X-ray powder diffraction. The FT-IR and FT-Raman spectra of complexes have been recorded in the region of 3500-400cm(-1) and 3500-100cm(-1), respectively. General information was acquired about structural properties of these complexes from FT-IR and FT-Raman spectra by considering changes at characteristic peaks of the cyano group and 3AP. The splitting of the ν(CN) stretching bands in the FT-IR spectra for complexes indicates the presence of terminal and bridging cyanides. The thermal behaviors of these complexes have been also investigated in the range of 25-950°C using TG and DTG methods. Magnetic susceptibility measurements were made at room temperature using Gouy-balance.

Five novel dicyanidoaurate(i)-based complexes exhibiting significant biological activities: synthesis, characterization and three crystal structures

Herein the anticancer, antibacterial, and antifungal effects of the five novel dicyanidoaurate(i)-based complexes have been reported.

Two novel cyanido-bridged polymeric complexes with suspension bridge type connections and a series of related complex salts: crystallographic and thermal characterizations

Polymeric complexes exhibiting interesting suspension bridge type binding and dissimilarity in complex formation behavior of 8B group members were studied.

New cyano bridged heteropolynuclear Cu(II) and Cd(II)-tetracyanopalladate(II) polymeric complexes with 2-methylimidazole ligand

New cyano-bridged heteronuclear polymeric complexes, [M(mim)2Pd(CN)4]n (M=Cu(II) (1) or Cd(II) (2); mim=2-methylmidazole), have been synthesized and characterized by elemental, thermal, FT-IR and Raman spectral analyses. The crystal structure of complex 1 has been determined by single crystal X-ray diffraction technique. The crystallographic analysis reveals that it crystallizes in the monoclinic system, space group P21/c. The Pd(II) atom is coordinated by four cyano ligands, while Cu(II) atom is also surrounded by the two mim and two cyano ligands. The structure of 1 is formed by infinite 2,2-TT type chains of the [-Cu(mim)2-NC-Pd(CN)2-CN-]n composition; these are interlinked by hydrogen bonds (HBs) leading to two-dimensional patterns. FT-IR and Raman spectral data indicate the presence of bridging cyano ligands in the structures of the complexes.

Synthesis and characterization of two novel dicyanidoargentate(i) complexes containing N-(2-hydroxyethyl)ethylenediamine exhibiting significant biological activity

Two novel cyanido-complexes having very significant antibacterial, antifungal and anticancer activities in vitro were synthesized and characterized using various techniques.

Two dimensional cyano-bridged heteropolynuclear complex containing Pd ···π interactions

The heteronuclear complex, [Cd(NH3)2(μ-ampy)Pd(μ-CN)2(CN)2] n (1) (ampy = 4-aminomethylpyridine), was synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, elemental and thermal analyses and single crystal X-ray diffraction techniques. The complex crystallizes in the triclinic system, space group P-1. The Cd(II) ion exhibits a distorted octahedral coordination by two different N-atoms from two symmetrically equivalent ampy ligands, two ammine ligands and two bridging cyano groups, whereas the Pd(II) ion has square planar coordination and is coordinated by four cyano ligands. The tetracyanopalladate(II) anion is coordinated to the adjacent two Cd(II) ions to generate a one-dimensional chain. The adjacent 1D chains are connected by the μ-ampy bridging ligands to form a 2D network. The 2D layers are further linked by Pd···π and hydrogen bonding interactions to generate a 3D supramolecular network. The decomposition reaction takes places in the temperature range of 40–900 °C in the static air atmosphere.