Keiichi Adachi

The rational syntheses of manganese-chloranilate compounds: crystal structures and magnetic properties

[Mn(CA)(terpy)] n ( 1 ) and {[Mn(CA)(bipym) 0.5 (H 2 O)](H 2 O)(C 2 H 5 OH)} n ( 2 ) (H 2 CA=chloranilic acid, terpy=2,2′:6′,2″-terpyridine and bipym=2,2′-bipyrimidine) have been synthesized and their crystal structures determined by a single-crystal X-ray diffraction. Compound 1 is made up of infinite chains of chloranilate-bridged manganese(II), affording a zig–zag pattern, with terpyridine ligands stacking between the chains. Compound 2 has a novel honeycomb layered structure, where each hexagon consists of six Mn(II) ions, four CA 2− and two bipym ligands. Mn(II) ions in both compounds are unusually hepta-coordinated. Magnetic susceptibility measurements of both compounds show weak antiferromagnetic coupling between the nearest Mn(II) ions.

Crystal structures and magnetic properties of novel coordination polymers with rectangular lattice constructed from pyrazine derivative

Abstract The two-dimensional copper(II) coordination polymers {[Cu(tdpd)(pyz)](H2O)}n (1) and {[Cu(tdpd)(4,4′-bpy)](H2O)3}n (2) (H2tdpd=1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile; pyz=pyrazine; 4,4′-bpy=4,4′-bipyridine) have been synthesized and characterized. Compounds 1 and 2 consist of two-dimensional rectangular arrays of copper(II) ions and interstitial waters. Each copper ion has a distorted octahedral coordination. The magnetic susceptibility data of 1 over a range of 2–300 K were analyzed by using the Heisenberg linear chain theory with a mean field approximation. The obtained J and zJ′ values are −5.9 and −1.1 cm−1, respectively.

Novel layered structures constructed from iron-chloranilate compounds

Abstract Novel hydrogen bond-supported intercalation compounds, {(G) m [Fe(CA) 2 (H 2 O) 2 ]} n (CA 2− =chloranilate, G=guest molecules) have been synthesized and characterized. The compound {(Hpy)[Fe(CA) 2 (H 2 O) 2 ](H 2 O)} n (py=pyridine) ( 1 ) crystallizes in the triclinic, space group P 1 (#2), with a =9.537(5), b =13.563(6), c =9.231(4) A, α =107.18(4), β =102.33(4), γ =102.12(4)°, V =1065.9(10) A 3 , and Z =2. Compound {(H 2 bipy)[Fe(CA) 2 (H 2 O) 2 ] 2 (H 2 O) 2 } n (bipy=4,4′-bipyridine) ( 2 ) crystallizes in the triclinic, space group P 1 (#2), with a =9.101(1), b =10.379(1), c =12.802(2) A, α =79.45(1), β =82.67(1), γ =66.32(1)°, V =1086.8(3) A 3 , and Z =1. The structure of 1 consists of mononuclear [Fe(CA) 2 (H 2 O) 2 ] − anions, Hpy + cations and uncoordinated water molecules. Four oxygen atoms of two CA 2− anions and two oxygen atoms from two water molecules are coordinated to the iron ion making anionic building blocks of the host layer. The compound of 2 contains the similar monomeric building blocks, H 2 bipy 2+ cations and uncoordinated water molecules. In both the compounds the coordination geometry of the building blocks are distorted octahedron, where two water molecules sit on the trans position in 1 and on the cis position in 2 . In compound 1 the [Fe(CA) 2 (H 2 O) 2 ] − anions make a two-dimensional (2-D) layer supported by hydrogen bonds. Hpy + ions are included in between the layers of 1 supported by hydrogen-bonding and electrostatic interaction with the host layers. In compound 2 the coordinated chloranilate rings of [Fe(CA) 2 (H 2 O) 2 ] − anions are stacked upon each other and make a layer with the help of hydrogen bonds. H 2 bipy 2+ cations are included in between the layers supported by hydrogen bonding, electrostatic and stacking interaction with coordinated CA 2− ions. The 57 Fe Mossbauer spectra of the compounds show that the oxidation state of iron is 3 with IS=0.41 ( 1 ) and 0.39 mm s −1 ( 2 ); QS=0.83 ( 1 ) and 1.29 mm s −1 ( 2 ) at 296 K, respectively. Compound 2 shows weak antiferromagnetic interaction over the crystal ( θ =−2.3 K).

Proton-transfer-mediated crystal engineering using 1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile with 4,4′-bipyridine

The crystal structure of a salt [Hbpy][Htdpd] (1) (bpy = 4,4′-bipyridine, H2tdpd = 1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile) is reported; the supramolecular structure is rationally designed via hydrogen bonding interactions.

Calorimetric Study of Correlated Disordering in [Hdamel]2[CuII(tdpd)2]·2THF Crystal

The heat capacity of [Hdamel]2[Cu(II)(tdpd)2] x 2 THF was measured from 6 to 250 K by adiabatic calorimetry. There are four heat anomalies around 150 K associated with disordering in the orientation of the uncoordinated THF molecules and in the conformation of the out-of-plane allyl groups of [Hdamel](+) units. The total entropy of transition was determined to be 19.8 J K(-1) mol(-1), less than the 4R ln 2 (R = gas constant) expected from the crystal structure at room temperature. The smallness of the total entropy change on phase transitions proves the presence of the strong motional correlation between the adjacent allyl groups. The calorimetric conclusion agreed with the crystal structure at 200 K re-examined in this study.

Triple Hydrogen Bond Directed Crystal Engineering of Metal Assembled Complexes: The Effect of a Novel Organic-Inorganic Module on Supramolecular Structure

The new manganese(II) and zinc(II) triply hydrogen-bonded complexes [Hmel] 2 [M(tdpd) 2 (OH 2 ) 2 ]2H 2 O (M = Mn 2+ ( 2 ); Hmel + = melaminium cation; H 2 tdpd = 1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile) have been synthesized and characterized. These complexes are isostructural as revealed by their single crystal structure analyses. Both the compounds are composed of triply hydrogen-bounded module of the AAA L DDD system. triple hydrogen bonding manganese zinc

Synthesis and Crystal Structure of One-Dimensional Copper(II) Coordination Polymer Bridged by Pyrazine Derivative

The one-dimensional copper(II) coordination polymers [Cu(tdpd)(pda)] n ( 1 ) (H 2 tdpd=1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile, pda=1,2-phenylenediamine) has been synthesized and characterized. Compund 1 is a linear chain of copper(II) ions bridged by tdpd 2− dianion with terminal pda ligand. Magnetic susceptibility measurement shows antiferromagnetic couplings between the copper(II)ions.

One-dimensional helical chain in the co-crystal of CHCl3 and trans-2,3,5,6,11,11b-hexahydro-3-oxo-1H-indolizino[8,7-b]indole-5-carboxylic acid methyl ester: a channel-type inclusion complex

X-Ray analysis of the title co-crystal shows a channel-type inclusion structure. The helical network of the indolizino–indole moiety contains a helical arrangement of CHCl3.

Iron-Chloranilate Intercalation Compounds: Synthesis, Crystal Structures, and Thermal Properties

Abstract Hydrogen bond supported new iron-chloranilate assemblies, {(Hpy)[Fe(CA)2(H2O)2](H2O)}n (py = pyridine, H2CA = chloranilic acid, C6H2O4Cl2) (1), and [(phz)2[Fe(CA)2(H2O)2](H2O)2]n (phz = phenazine, C12H8N2) (2) have been synthesized and characterized. Compound 2 crystallizes in the monoclinic, space group C2/m (#12), with a= 29.135(6) Å, b= 16.886(6) Å, c = 15.017(5) Å, ß = 165.907(1)°, V= 1798(2) Å3, Z = 2. In both the compounds two chloranilate dianions and two water molecules are coordinated to the iron ion making anionic monomers [Fe(CA)2(H2O)2]−, which are the building blocks of the compounds. The coordination environment around the iron ion in the building block is a distorted octahedron, where two water molecules sit on the trans position to each other. [Fe(CA)2(H2O)2]− anions form common layer structures, supported by hydrogen bonds. Hpy+ are intercalated in between the layers of 1 by electrostatic and hydrogen bonding interactions and phz are intercalated in that of 2 by electrostatic interactions. DSC traces of 1 show anomaly at 174 K, indicating phase transition in the compound.

Crystal Structure and Magnetic Property of Cobalt(II) Assembled Compound, {[Co(CA)(bipym)](H2O)2}n (H2CA = chloranilic acid, bipym = 2,2′-bipyrimidine)

Abstract Cobalt(II) assembled complex compound, {[Co(CA)(bipym)](H2O)2}n(H2CA = chloranilie acid, bipym = 2,2′-bipyrimidine) (1) has been synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystalizes in the monoclinic, space group C2/c(#15), with a = 16.652(4) Å, b = 11.163(3) Å, c = 10.081(3) Å, β = 116.12(2)°, V = 1682.4(7) Å3, Z = 4. The bipym ligands bridge the cobalt centers in bis-bidentate fashion and make zigzag chains. The chains form layer structures by stacking interaction and hydrogen bonding interaction with the help of interstitial water molecules. The temperature dependence of the magnetic susceptibility of 1 shows intramolecular antiferromagnetic interaction with θ = - 39.7 K.