Several unusual complexes of ytterbium(ii) stabilised by coordination to mixed O4X2-donor macrocyclic ligands (X = O, NH, S or Se) are described. Distorted 8-coordination is evident from the crystal structure of the neutral [YbI2([18]aneO4Se2)], forming the first reported example of Yb(ii)-selenoether coordination.

Crystalline complexes of some alkali and alkaline earth Perchlorates and picrates with macrocyclic polyethers have been synthesized. With the alkyl substituted aromatic macrocyclic polyethers bis(3,5-di-£er£-butylbenzo)-18-crown-6 and bis(4-hexadecylbenzo)-18crown-6 it was not possible to isolate all the complexes in the crystalline form. In fact the steric hindrance, caused by the alkyl substi...

Extending to transition metals, the class of compounds known as inverse crown ethers, two mixed alkali metal-manganese(II) amide ring compounds with oxo cores have been synthesised and crystallographically characterised, together with an oxo-free alkyl-amido precursor.

[2]Rotaxanes based on the 1,2-bis(pyridinium)ethane subset[24]crown-8 ether motif were prepared that contain a terminal terpyridine group for coordination to a transition-metal ion. These rotaxane ligands were utilized in the preparation of a series of heteroleptic [Ru(terpy)(terpy-rotaxane)]2+ complexes. The compounds were characterized by 1D and 2D 1H NMR spectroscopy, X-ray crystallography, ...

A Competitive spectrophotometric method has been used for the study of complexation between Cu2+, Zn2+ and Cd2+ (M) and 18-crown-6(18C6, B) in methanol using 4-(2-thiazolylazo) resorcinol (TAR, HL) as the colorimetric complexant. Absorption spectra of the species in the M-TAR-18 C6 system at a various concentrations of 18C6 showed no formation of ternary com...

In this work, an attempt to synthesize zero-valent Ni nanoclusters using the Brust method resulted in an unexpected material, Ni₆(SCH₂CH₂Ph)₁₂, which is a nanoscale Ni(ii)-phenylethanethiolate complex and a hexameric, double-crown-like structure, as determined by a series of characterizations, including mass spectrometry (MS), thermal gravimetric analysis (TGA), single-crystal X-ray diffraction...

The Association equilibrium constants of complexes between some -amino acids (Alanine, Valine, Leucine, Arginine, Aspartic acid, Glutamic acid, Histidine and Lysine) with 1, 3-dimethoxy, 2, 4dithiolCalix[4]crown-5-ether in chloroform and methanol mixed solvent (50%: 50%, V:V) have been investigated by means of UV/Vis spectrophotometry titration. On the basis of complexation formation values, it...