Cyclen derivatives with two trans-methylnitrophenolic pendant arms: a structural study of their copper(II) and zinc(II) complexes
authors Esteves, CV; Lima, LMP; Mateus, P; Delgado, R; Brandao, P; Felix, V
nationality International
journal DALTON TRANSACTIONS
keywords NITROPHENOL SIDE ARMS; METAL-COMPLEXES; CRYSTAL-STRUCTURES; PHENOL-PENDANT; MACROCYCLIC LIGAND; ACID; STABILITY; STEREOCHEMISTRY; COORDINATION; CHEMISTRY
abstract Two new cyclen derivatives, H(2)do2nph and H(2)cb-do2nph, containing two trans-2-methyl-4-nitrophenol pendant arms and the latter including also an ethylene cross-bridge, were prepared in good yields using the bisaminal synthetic route. The two ligands were studied comparatively regarding their metal complexation behaviour. The copper(II) and zinc(II) complexes of H(2)do2nph and H(2)cb-do2nph were studied in dimethylsulfoxide-water (9 : 1 v/v) solution by a range of spectroscopic techniques. Copper(II) complexes were also studied in solid state by X-ray single crystal diffraction. These studies showed that the copper(II) and zinc(II) complexes of H(2)do2nph exhibited a distorted square pyramidal coordination environment with the four nitrogen atoms of the cyclen ring defining the basal plane, and that one of the nitrophenolate arms did not coordinate to the metal, independently of its protonation state. On the other hand, depending on the protonation state of one of the nitrophenolic arms, the cross-bridged derivative forms copper(II) complexes with distorted square pyramidal or octahedral geometries with one or two arms coordinated to the metal centre, respectively. In the complex with distorted octahedral geometry, the two phenolic oxygen atoms are coordinated to the metal centre in a cis-fashion. Acid-assisted dissociation assays in 1 mol dm(-3) HCl DMSO-H2O (9 : 1 v/v) solution at 298.2 K allowed one to determine the half-life of both copper(II) complexes, which is lower for the derivative without a cross-bridge as expected, while for the other one it is quite high and in line with similar cross-bridged cyclen derivatives from the literature.
publisher ROYAL SOC CHEMISTRY
issn 1477-9226
year published 2013
volume 42
issue 17
beginning page 6149
ending page 6160
digital object identifier (doi) 10.1039/c2dt32363j
web of science category Chemistry, Inorganic & Nuclear
subject category Chemistry
unique article identifier WOS:000317013000020
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 4.099
5 year journal impact factor 3.872
category normalized journal impact factor percentile 87.778
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg