Tian-Huey Lu

A precise structure redetermination of nickel ammonium sulfate hexahydrate, Ni(H2O)6.2NH4.2SO4

The Ni(H 2 O), ion is located at an inversion center. Six octahedral water molecules surround the Ni II ion and form hydrogen bonds with the sulfate groups. Each ammonium group binds to the sulfate groups through hydrogen bonds

A selenium-bridged mixed-metal cluster, (CO)5(PPh3)2FePt2(μ3-Se)

Stirring at room temperature of [(CO) 6 Fe 2 {μ-SeC(H)= C(CH 2 OH)Se}] with Pt(PPh 3 ) 4 or Pt(C 2 H 4 )(PPh 3 ) 2 in dichloromethane affords the μ 3 -Se-bridged mixed-metal cluster pentacarbonyl-1κ 3 C,2κC,3κC-μ 3 -selenido-1:2:3κ 3 Se-bis(triphenylphosphine)-2κP,3κP-irondiplatinum(2 Fe-Pt), [FePt 2 (μ 3 -Se)(C 18 H 15 P) 2 (CO) 5 ]. The structure can be described as an FePt 2 Se butterfly; each Pt atom is coordinated by one CO and one PPh 3 group, whereas the Fe atom is bonded to three CO groups. The Fe atom is in a distorted octahedral environment. The bridging Se atom is bonded to the open triangular array of FePt 2 in a μ 3 coordination mode. The geometry around the Pt atoms is distorted square planar.

(5,5-Dimethyl-4,7-diazadecane-1,10-diamine-N,N',N'',N''')(perchlorato-O)copper(II) perchlorate

The Cu II ion in the title complex, [Cu(ClO 4 )(C 10 H 26 N 4 )]ClO 4 , is five-coordinate with four N atoms equatorial and one perchlorato O atom axial. The two asymmetric N atoms are of the same R or S configuration. Each six-membered ring is in a stable chair conformation and the central five-membered ring is in a skew form. Hydrogen bonds help stabilize the crystal structure

Bis[2-(1,3-benzothiazol-2-yl)phenolato-O,N]chlorooxorhenium(V)–dichloromethane (1/1.5)

The X-ray structure of the title compound, [Re-(C 13 H 8 NOS) 2 ClO].1.5CH 2 Cl 2 , shows distorted octahedral coordination geometry around rhenium. Bond lengths and angles are typical of related rhenium and technetium complexes. The average Re-N and Re-O distances are 2.140 (4) and 1.977 (4) A, respectively. The Re=O and Re-Cl distances are 1.679 (4) and 2.365 (1) A, respectively.

Structure of [(3RS,7SR)-3,7-dimethyl-3,7-diazanonane-1,9-diamine]perchloratocopper(II) perchlorate, [Cu(ClO4)(C9H24N4)](ClO4)

The Cu II is coordinated in a slightly distorted square pyramid with the four N atoms equatorial and the 0 atom of the perchlorate group axial. The four donor N atoms are coplanar; Cu II is 0.0165 A out of this plane towards the perchlorate group. This complex has the (3RS,7SR) configuration at the chiral N centers, with the two N-methyl groups on the same side of the plane of the four N atoms. The tetraamine binds to the Cu II atom in a relatively strainfree planar fashion- the central six-membered ring exhibits a stable chair form and the two terminal five-membered rings take stable skew forms

cis-(Nitrato-O,O')[(1RS,4SR,5SR,8RS,11SR,12SR)-C-rac-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane-κ4N]nickel(II) nitrate

The crystal structure of the title compound, [Ni(NO 3 )-(C 14 H 32 N 4 )]NO 3 , was determined by X-ray diffraction. The Ni II ion is six-coordinate in a distorted octahedral arrangement, with the tetradentate macrocyclic ligand in a folded conformation. The two five-membered rings of the macrocyclic ligand have skew conformations, while the two six-membered rings adopt chair conformations. The four chiral N-atom centers are 1RS, 4SR, 8RS and I ISR, and the chiral C-atom centers are 5SR and 12SR.

trans-Diaqua(C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane-κ4N)nickel(II) dichloride

The crystal structure of the title compound, [Ni(C 14 H 32 N 4 )(H 2 O) 2 ]Cl 2 , has been determined by X-ray diffraction. The Ni II ion lies on an inversion center and is six-coordinate in a distorted octahedral geometry, with the four N atoms of the macrocyclic ligand equatorial and the two water molecules axial. The tetradentate macrocyclic ligand adopts a configuration having two six-membered rings in a chair form and two five-membered rings in a gauche form.

Two Conformational (Configurational) Isomers of Diperchlorato[(5RS,6RS,12SR,13SR)-5,6,12,13-tetramethyl-1,4,8,11-tetraazacyclotetradecane-κ4N]copper(II)

The crystal structure of the title compound, [Cu(ClO4)2(C14H32N4)], has been determined by X-ray diffraction. X-ray structure analysis reveals that, owing to disorder, the compound exists in two forms, A and B. The coordination polyhedron about the CuIIion is centrosymmetric. The CuII ion is six-coordinated in a distorted octahedral geometry, with the four N atoms of the macrocyclic ligand in equatorial positions and the two perchlorate O atoms in axial positions. The four chiral N-atom centres have a 1RS,4RS,8SR,11SR configuration and a 1SR,4RS,8RS,11SR configuration, respectively, for the two forms A and B. However, both have a 5RS,6RS,12SR,13SR configuration for the four chiral C-atom centres. Hydrogen bonds help stabilize the crystal structure.

Two Forms of (5,5-Dimethyl-4,7-diazadecane-1,10-diamine)nickel(II) Diperchlorate

The title Ni II complex, [Ni(C 10 H 26 N 4 )](ClO 4 ) 2 , crystallizes in yellow and orange forms. In both crystals, the stereochemistry and conformation of the complex cations are identical. Small differences arise from packing effects, differences in the orientations of the perchlorate groups and hydrogen bonding. The Ni II atom has square-planar coordination with the four tetraamine N atoms in equatorial positions. In each complex, the two chiral N-atom centres are in the (4RS,7RS) configuration. The tetraamine binds to the Ni II atom in a relatively strain-free planar manner; the central six-membered ring exhibits a stable chair conformation and the two terminal five-membered rings adopt stable skew forms

Structure of (2,5,9,13,16-pentaazaheptadecane)perchloratonickel(II) perchlorate, [Ni(ClO4)(C12H31N5)](ClO4)

The crystal structure of the title compound has been determined by X-ray diffraction. The coordination geometry about the Ni II ion is distorted octahedral. The two five-membered chelate rings are in skew forms and the two six-membered chelate rings are in chair forms. The configuration of the four chiral N centers is (2RS,5RS, 13SR, 16SR). Hydrogen bonds between the amine and perchlorate groups help stabilize the crystal