Synthesis and characterization of the pentadentate macrobicyclic ligand, 14-thia-1,4,8,11-tetraazabicyclo[9.5.3]nonadecane (L1) and its nickel(II) complexes. X-ray crystal structure of [Ni(L1)(ClO4)](ClO4)·2[Ni(L1)(OH2)](ClO4)2·6H2O

2001 ◽  
Vol 79 (5-6) ◽  
pp. 930-937 ◽  
Author(s):  
Kevin R Coulter ◽  
Alexander McAuley ◽  
Steven Rettig
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Axial Symmetry ◽  
Synthesis And Characterization ◽  
High Dilution ◽  
Subsequent Reduction ◽  
X Ray ◽  
Frozen Solution ◽  
Reversible Redox

The pentadentate macrobicycle,14-thia-1,4,8,11-tetraazabicyclo[9.5.3]nonadecane (L1), has been synthesized by high dilution cyclization of 1-thia-4,8-diazacyclododecane ([10]aneN2S) (2) with N,N'-bis(α-chloro acetamido) propane (3) and subsequent reduction of the di-oxo intermediate. The structure of the [Ni(L1)(ClO4)](ClO4)·2[Ni(L1)(OH2)](ClO4)2·6H2O complex (monoclinic, P21/c, a = 13.9261(4) Å, b = 30.279(2) Å, c = 17.1248(3) Å, β = 94.5065(3)°) at R = 0.039 (Rw = 0.034) for 911 parameters using 18 266 reflections with I > 3σI has been determined. The ligand adopts a trans-III configuration. The Ni(II) ion is pseudooctahedral with Ni-S = 2.3896(10) Å in [Ni(L1)(ClO4)]+ and 2.4193(10) Å, 2.4225(10) Å, in the two [Ni(L1)(H2O)]2+ cations. Both nickel(II) and nickel(III) complexes are six-coordinate in solution. Oxidation of the [Ni(L1)(OH2)]2+ complex with K2S2O8 in aqueous solution yielded an ESR active Ni(III) species and the frozen solution spectrum displayed axial symmetry with g[Formula: see text] = 2.159 and g|| = 2.024. In CH3CN, the [Ni(L1)(solv)]2+ complex showed two reversible redox waves corresponding to the Ni2+/+ couple at E1/2 = -1.807 V vs. Fc+/0 and Ni3+/2+ couple at E1/2 = 0.715 V vs. Fc+/0.Key words: synthesis, structure, polydentate macrobicycle, nickel(II).

The synthesis and characterization of the pendant-armed ligand N,N′-bis(2′-pyridylmethyl)-1,7-dithia-4,11-diazacyclotetradecane (L4) and crystal structures of L4 and the copper(II) complex [Cu(L4)](ClO4)2 — Crystal structure of the nickel(II) complex of N-(2′-pyridylmethyl)-1,4,7-trithia-11-azacyclotetradecane (L2), [Ni(L2)(CH3CN)](ClO4)2·CH3CN

2006 ◽  
Vol 84 (2) ◽  
pp. 187-195 ◽  
Author(s):  
B CM Chak ◽  
A McAuley
Keyword(s):  
Crystal Structure ◽  
Copper Ion ◽  
Esr Spectra ◽  
Synthesis And Characterization ◽  
Electrochemical Studies ◽  
High Dilution ◽  
Donor Ligand ◽  
X Ray ◽  
Distorted Octahedral

The synthesis and characterization of the mixed donor ligand N,N′-bis(2′-pyridylmethyl)-1,7-dithia-4,11-diazacyclotetradecane (L4) containing two pendant pyridine arms is described. The macrocycle formation involves reaction of N-tosylbis(2-bromoethyl)amine with N-tosylbis(3-mercaptopropyl)amine at high dilution followed by detosylation at the nitrogen atoms using LiAlH4 in view of the presence of the thioether groups. An X-ray study of the ligand shows the sulphur atoms lie exo to the macrocyclic ring. The nickel(II) and copper(II) complexes of L4 have been characterized and the X-ray structure of the Cu(II) ion exhibits a five-coordinate copper ion despite the presence of six available donor atoms. In the case of ligand N-(2-pyridylmethyl)-1,4,7-trithia-11-azacyclotetradecane (L2), with a single pendant N donor, the Ni(II) complex is distorted octahedral with a molecule of acetonitrile in the sixth site. Details of UV–vis, ESR spectra, and electrochemical studies on the complexes are presented.Key words: synthesis, pendant-armed, mixed donor S,N macrocycles, copper, nickel.

Darstellung und Charakterisierung von Rubidiumhydrogencyanamid/Synthesis and Characterization of Rubidium Hydrogen Cyanamide

1999 ◽  
Vol 54 (11) ◽  
pp. 1375-1378 ◽  
Author(s):  
Michael Becker ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Liquid Ammonia ◽  
Synthesis And Characterization ◽  
Hydrogen Cyanamide ◽  
X Ray ◽  
Bond Lengths

The synthesis of RbHCN2 was carried out by reaction of cyanamide with rubidium amide in liquid ammonia. The crystal structure has been determinedo by x-ray powder methods (orthorhombic, P21,21,21, a = 7.299(1), b = 9.435(1), c = 9.420(1) Å; Z = 8). The anion is slightly bent (174°) and exhibits two different bond lengths (C-N: 1.17, HN-C: 1.31 Å).

The synthesis and characterization of a cationic technetium(V) phenylimido complex. The X-ray crystal structure of [TcCl2(NPh)(PMe2Ph)3](BPh4)

1995 ◽  
Vol 230 (1-2) ◽  
pp. 205-208 ◽  
Author(s):  
Terrence Nicholson ◽  
Alan Davison ◽  
Jon A. Zubieta ◽  
Qin Chen ◽  
Alun G. Jones
Keyword(s):  
Crystal Structure ◽  
Synthesis And Characterization ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document