Stabüity Constants, Metal Ion Complexes, Oxygen Tripod Ligand The formation of metal ion complexes ML(> and ML2(>+ of the oxygen tripod ligand L~ = cyclopentadienyltris(diethylphosphito-P)cobaltate(l-) with metal ions M — Li+, Na+, K+, Mg+, Ca+, Sr+, Ba+, Mn+, Co+, Ni+, Cu+, Zn+, Cd+, Hg+, Pb+, Ag+, and La has been studied by pH titration at 25 °C in 95/5 methanol/water solutions kept at an ion...

Pedunculate oak (Quercus robur L.) forests in Slovenia are experiencing widespread mortality. Changes in lowlands are reflected in decline of complete forest complexes, high mortality, uneven stand structure and associated forest regeneration problems. Prediction of the present-tree response in disturbed forest ecosystems may significantly contribute to better guideline policies for the silvicu...

Initial attempts to make [Ni(H2O)2(15-crown-5)](NO3)2, i.e. to insert the Ni2+ ion into the 15-crown-5 macrocycle, gave the mono- (two polymorphs) and dihydrate of a co-crystal of[Ni(H2O)6](NO3)2 and 15-crown-5 (1,4,7,10,13-pentaoxacyclopentadecane=15C5). Synthetic routes designed to restrict the water available to the Ni2+ cation gave three additional compounds, [Ni(H2O)6](NO3)2-trans-[Ni(H2O)...

A new library of ionophoric p-tert-butylcalix[4]diquinones containing ester (1), primary, secondary, and tertiary amide (2-4), and crown ether (5) substituents has been synthesized by treatment of the respective 1,3-bis-substituted p-tert-butylcalix[4]arene with Tl(OCOCF(3))(3) in trifluoroacetic acid. The structures of the free ligands 1 and 2, a p-tert-butylcalix[4]diquinone bridged at the lo...

Z. Naturforsch. 52 b, 615-619 (1997); received January 15, 1997 Crown Ether, Crystal Structure, Hydrate, Hydrogen Bonding, Melting Diagram The melting diagram of the system 18-crown-6/water has been set up and the existence of four binary hydrates confirmed. Crystal structures have been determined for three of these, in addition to that for the hexahydrate already published. The hydrates are mo...