The Hofman-type clathrate: M(NH3)2M′(CN)4 . 2G

Crystalline Sponge Method: X-ray Structure Analysis of Small Molecules by Post-Orientation within Porous Crystals-Principle and Proof-of-Concept Studies

This Review discusses, along with the historical background, the principles as well as proof-of-concept studies of the crystalline sponge (CS) method, a new single-crystal X-ray diffraction (SCXRD) method for the analysis of the structures of small molecules without sample crystallization. The method uses single-crystalline porous coordination networks (crystalline sponges) that can absorb small guest molecules within their pores. The absorbed guest molecules are ordered in the pores through molecular recognition and become observable by conventional SCXRD analysis. The complex {[(ZnI₂ )₃ (tpt)₂ ]⋅x(solvent)}_n (tpt=tris(4-pyridyl)-1,3,5-triazine) was first proposed as a crystalline sponge and has been most generally used. Crystalline sponges developed later are also discussed here. The principle of the CS method can be described as "post-crystallization" of the absorbed guest, whose ordering is templated by the pre-latticed cavities. The method has been widely applied to synthetic chemistry as well as natural product studies, for which proof-of-concept examples will be shown here.

Two-dimensional cyano-bridged coordination polymer of Mn(H2O)2[Ni(CN)4]: structural analysis and proton conductivity measurements upon dehydration and rehydration

The interlayer spaces in the two-dimensional cyano-bridged coordination polymer were found to be non-ionic and not proton conductive.

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.

Infrared and Raman study of some isonicotinic acid metal(II) halide and tetracyanonickelate complexes

In this study the M(IN)(2)Ni(CN)(4) [where M: Co, Ni, and Cd, and IN: isonicotinic acid, abbreviated to M-Ni-IN] tetracyanonickelate and some metal halide complexes with the following stoichiometries: M(IN)(6)X(2) (M: Co; X: Cl and Br, and M: Ni; X: Cl, Br and I) and Hg(IN)X(2) (X: Cl, Br, and I) were synthesized for the first time. Certain chemical formulas were determined using elemental analysis results. The FT-IR and Raman spectra of the metal halide complexes were reported in the 4000-0 cm(-1) region. The FT-IR spectra of tetracyanonickelate complexes were also reported in the 4000-400 cm(-1) region. Vibrational assignments were given for all the observed bands. For a given series of isomorphous complexes, the sum of the difference between the values of the vibrational modes of the free isonicotinic acid and coordinated ligand was found to increase in the order of the second ionization potentials of metals. The frequency shifts were also found to be depending on the halogen. The proposed structure of tetracyanonickelate complexes consists of polymeric layers of /M-Ni(CN)(4)/(infinity) with the isonicotinic acid molecules bound directly to the metal atom.

Hexacyanocobaltate(III) Anions as Precursors of Co(II)−Ni(II) Cyano-Bridged Multidimensional Assemblies: Hydrothermal Syntheses, Crystal and Powder X-ray Structures, and Magnetic Properties

Three novel cyanide-bridged heterobimetallic coordination polymers have been synthesized by hydrothermal routes, in superheated water solutions, by using K3[Co(CN)6], NiCl2.6H2O, and alpha-diimine ligands: [Ni(CN)4Co(phen)] (1; phen = 1,10-phenanthroline), [Ni(CN)4Co(2,2'-bipy)] (2; 2,2'-bipy = 2,2'-bipyiridine), and [Ni(CN)4Co(2,2'-bipy)2] (3). The isostructural compounds 1 and 2 contain a two-dimensional network with Co(II) centers octahedrally coordinated by one chelating 2,2'-bipy ligand and four cyanide groups of four distinct [Ni(CN)4]2-, through crystallographically equivalent, bridging units. Compound 3 contains one-dimensional zigzag chains in which the Co(II) ion is coordinated by two chelating 2,2'-bipy ligands and two cyanides from two different [Ni(CN)4]2- units cis to each other. These compounds have been fully characterized by single-crystal or unconventional powder X-ray diffraction analyses and variable-temperature magnetic measurements.

[Au(CN)4]- as a supramolecular building block for heterobimetallic coordination polymers

A series of the first coordination polymers using the [Au(CN)(4)](-) anion as a building block has been prepared. The planar tetracyanoaurate anion uses one, two, or four cyano groups to bridge to Ni(II) or Cu(II) centers and exhibits weak Au(III)-N(cyano) interactions between anions. Ni(en)(2)[Au(CN)(4)](2).H(2)O (1, en = ethylenediamine) is a molecular compound with the two [Au(CN)(4)](-) anions coordinating in a trans orientation to Ni(II) without further cyanide coordination. Cu(dien)[Au(CN)(4)](2) (2, dien = diethylenetriamine) forms a similar molecular complex; however, the dimensionality is increased through weak intermolecular Au-N(cyano) interactions of 3.002(14) A to form a 1-D zigzag chain. Cu(en)(2)[Au(CN)(4)](2) (3) also forms a molecular complex similar to 1, but with elongated axial bonds. The complex further aggregates through Au-N(cyano) interactions of 3.035(8) A to form a 2-D array. In [Cu(dmeda)(2)Au(CN)(4)][Au(CN)(4)] (4, dmeda = N,N-dimethylethylenediamine) one [Au(CN)(4)](-) anion coordinates via two cis-N(cyano) donors to the axial sites of two Cu(II) centers to form a 1-D zigzag chain of alternating [Cu(dmeda)(2)](2+) and [Au(CN)(2)](-) units; the other [Au(CN)(4)](-) anion forms a 1-D chain via Au-N(cyano) interactions. In [Cu(bipy)(H(2)O)(2)(Au(CN)(4))(0.5)][Au(CN)(4)](1.5) (5, bipy = 2,2'-bipyridine) one [Au(CN)(4)](-) anion uses all four cyano moieties to bridge four different Cu(II) centers, creating a 1-D chain.

Vibrational spectroscopic study on pyrimidine metal(II) tetracyanometalate complexes

The results of an infrared and Raman spectroscopic study are reported for seven new metal(II) pyrimidine tetracyanonickelate complexes, M(pyr)2Ni(CN)4 [where (pyr) = pyrimidine; M = Mn, Fe, Co, Zn, Ni, Cu or Cd] and an IR spectroscopic study is presented for new cadmium pyrimidine tetracyanometalate complex, Cd(pyr)2Cd(CN)4. The spectral data suggest that the first seven compounds belong to the Hofmann-type and the last compound belongs to the Hofmann-Td-type of complexes.