Jan Janczak — Page 2 | Search PubMed

PubMed2002

Melaminium acetate acetic acid solvate monohydrate.

The crystals of the title new melaminium salt, 2,4,6-triamino-1,3,5-triazin-1-ium acetate acetic acid solvate monohydrate, C(3)H(7)N(6)(+).CH(3)COO(-).CH(3)COOH.H(2)O, are built up from singly protonated melaminium residues, acetate anions, and acetic acid and water molecules. The melaminium residues are interconnected by N-H...N hydrogen bonds to form chains along the [010] direction. These chains of melaminium residues form stacks aligned along the a axis. The acetic acid molecules interact with the acetate anions via the H atom of their carboxylic acid groups and, together with the water molecules, form layers that are parallel to the (001) plane. The oppositely charged moieties interact via multiple N-H...O hydrogen bonds that stabilize a pseudo-two-dimensional stacking structure.

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PubMed2001

Tetrakis[phthalocyaninato(2-)antimony(III)] hexadecaiodotetraantimony(III).

Crystals of a new antimony(III) phthalocyanine complex with the formula [Sb(C32H16N8)]4(Sb4I16), or (SbPc)4+*[Sb(4)I(16)]4-, where Pc is phthalocyaninate, have been obtained by the reaction of pure powdered antimony with phthalonitrile under a stream of iodine vapour. The crystals are built up from separate but interacting (SbPc)+ cations and centrosymmetric [Sb4I16]4- anions. Each Sb atom of two independent (SbPc)+ units is bonded to the four isoindole N atoms of the phthalocyaninate(2-) macrocycle and lies 1.0 A out of the plane defined by four isoindole N atoms. The anionic part of the complex consists of four SbI6 distorted octahedra joined together into a centrosymmetric [Sb4I16]4- anion. The arrangement of oppositely charged moieties in the crystal is mainly determined by ionic attraction and by a set of distinct donor-acceptor interactions between (SbPc)+ and [Sb4I16]4- ions.

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PubMed1999

Mixed-Valence, Disordered Structures and Characterization of Iodine-Doped Phthalocyanines: [YbPc(2)]I(2) and [(AsPc)(Pc)]I(2).

Crystals of C(64)H(32)N(16)YbI(2) and C(64)H(32)N(16)AsI(2) were grown directly in the reaction of ytterbium or arsenic powder with 1,2-dicyanobenzene under a stream of iodine at 200 degrees C. Both partially oxidized phthalocyanine complexes crystallize in the P4/mcc space group of the tetragonal system with one molecule per unit cell, with the cell dimensions a = 13.927(2) Å, c = 6.409(1) Å, and a = 13.926(2) Å, c = 6.433(1) Å for the Yb and As complexes, respectively. The space group of P4/mcc requires that both heavy (iodine and metal) atoms are disordered in these structures. The structures show columnar pseudo-monodimensional stacks of [YbPc(2)] or [(AsPc)(Pc)] units with an average nonintegral charge of +(2)/(3) and linear chains of triiodide I(3)(-) ions, which were detected by Raman spectroscopy. The monodimensional chains of I(3)(-) ions and pseudo-monodimensional aggregates of [YbPc(2)](2/3+) or [(AsPc)(Pc)](2/3+) are aligned along the c-axis of the crystals. The Yb(3+) ion lies in the center, whereas in the [(AsPc)(Pc)] unit the As(3+) ion does not lie in the center between the Pc rings. In the crystal of [(AsPc)(Pc)]I(2) both components in the [(AsPc)(Pc)](2/3+) unit (e.g., AsPc and Pc) with opposite charge are electrostatically interacting. The magnetic susceptibility measurement of the [YbPc(2)]I(2) shows typical Curie-Weiss behavior, and the effective magnetic moment is about 4.60 &mgr;(B). The EPR measurement shows no signal for the Yb complex, while for [(AsPc)(Pc)]I(2) two signals are observed: a sharp narrow line at g = 2.0028 of width approximately 2 G and a broad line at g = 2.0036 of width approximately 9 G. The two EPR signals are associated with two different radical components: a phthalocyaninato (Pc(-)(*)) ring and [AsPc(-)(*)], respectively. Both free radicals are in resonance: [(As(3+)Pc(2)(-))(Pc(-)(*))] <--> [(As(3+)Pc(-)(*))(Pc(2)(-))]. Oxygen effects on the EPR signal of the [(AsPc)(Pc)]I(2) crystal have been detected. The conductivity measured on polycrystalline samples at room temperature equals 2.5-4 x 10(-)(2) and 2.2-3.5 x 10(-)(4) Omega(-)(1) cm(-)(1) for [YbPc(2)]I(2) and [AsPc(Pc)]I(2), respectively. Both complexes exhibit nonmetallic character in conductivity (dsigma/dT > 0).

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