[en] The creation of new, more effective drugs against the harmful effects of various physical and chemical factors is even more relevant today. Therefore, in recent years, much research has been done on the development of low-toxic drugs, which have a wide range of pharmacological effects that regulate biochemical processes and hormonal balance within the body. Studies show that nitrogen-containing heterocyclic compounds greatly enhance the body's internal protective mechanisms, including its ability to detoxify active forms of oxygen.

[en] This review of the inorganic and coordination chemistry of zinc and cadmium covers material which appeared in volumes 102 and 103 of Chemical Abstracts. Zinc and cadmium are treated together and, as was the case last year, much of the reported chemistry is routine and has not been reported in detail. Rigorous classification of ligands continues to be a difficulty for compounds containing several different potential donor atoms and the reader may need to refer to more than one section. Although the scopeof this review does not encompass bio-inorganic in general, some more interesting aspects of application of ¹¹³Cd probes for biological systems have veen included this year. (author). 164 refs.; 9 schemes

[en] Some sterically very bulky salicylaldimine ligands were designed and prepared. In the ligand framework, bulky aryl substituents were installed on the ortho position of the salicylaldimine backbone as well as the ortho position of the aniline moiety. Subsequently, the corresponding zinc complexes were prepared and characterized. The zinc complexes bearing electron-withdrawing and bulky substituents on both positions showed much higher activity and much better controlled behavior in the ring opening polymerization of ε-caprolactone than the complexes bearing sterically less bulkier alkyl substituents. Graphical abstract:

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[en] It is showed that at use of the methods of the crossing curves and p H-metric titration and programme New DALSFEK at interaction of the Zn²⁺ and dipeptide H-Gly-Trp-OH at equivalent amounts in diluted water solutions [Zn L]^+, [ZnL₂]^0, [Zn(Hl)]²+^and [Zn(Hl₂)]²+^and the decimal logarithms of the constants formation lgK_[Zn L]=7.275, lgK_[ZnL₂]=14.055, lgK_[Zn(H L)]=12.645, lgK_[Zn(H L)₂]=30.111

[en] The tripodal quinolinyl chelator tachquin demonstrates a strong preference for octahedral coordination geometry with the average twist angle (α) of 53.7(8). The steric effect of the bulk quinolinyl is pronounced and resulted that one of the pendent arms of the title compound is disordered with two different positions of the 2-methylquinilinyl arm with C27A to C36A at 50% occupancy and with C27B to C36B at 50% occupancy, respectively. Ligands derived from the cis-1,3,5-triaminocyclohexane (tach) framework have shown versatility in binding transition metal ions of varied charges and sizes. Derivatizations of the triamine framework in order to prepare hexadentate chelators based on the tach have been succeeded by addition of the 2-methylpyridyl pendant arms (tachpyr in Fig. 1), by preparation of the N-alkylated derivatives of tachpyr ((NMe)₃tachpyr and (N-Et)₃tachpyr), and by preparation of the pyridine-ring alkylated tachpyr derivatives (tach-n-Me-pyr, n = 3-6). The tachpyr ligand forms a nearly octahedral complex with Zn(II) (0.88 A), while it forms a complex intermediate between octahedral and trigonal-prismatic with Cd(II) (1.09 A) and a slightly distorted trigonal-prismatic complex with Hg(II) (1.16 A) exhibiting effects of metal radius on coordination geometry. The tachpyr also have been demonstrated to affect the cellular iron metabolism of tumor cells, and to be quite cytotoxic to a variety of tumor cells as seen by an IC50 of 4.8 μM toward cultured bladder tumor cells

[en] We have developed a C₂ symmetric N₂O₂ ligand that forms only a single isomer of an octahedral Zn(II) complex. The rigidity of the complex allows detailed understanding of molecular recognition of dpen and dach. The tactical placement of N-(2-cyanoethyl) substitution in the host diamine was found to be critical in the chiral recognition for both electronic and steric reasons; the electronic effect of the cyanoethyl groups in 4 results in slowing down the rate of dissociation of dpen from the metal and the steric effect of the cyanoethyl groups results in increasing the stereoselectivity of the recognition. Rigid and C₂ symmetric chiral ligands are useful for crafting stereoselective catalysts. Binol, binap, dpen, dach, pybox, and salen ligands are just some of the 'privileged' C₂ symmetric ligands that have been used to construct a wide variety of interesting metal complexes as stereoselective catalysts. The C₂ symmetric N₂O₂ salen ligand forms trans octahedral complex. It is uncommon to find C₂ symmetric N₂O₂ ligands that form only one kind of cis octahedral complexes. For example, can in principle form three isomers of octahedral complexes (cis-α, cis-β or trans). In contrast, and should form only the C₂ symmetric cis octahedral complexes (cis-α) due to the connectivity of the ligand

[en] Devices based on zinc complexes with sulphanylaminosubstituted ligands are characterized by dual function – electroluminescence (EL) and photosensitivity. Both EL and photosensitivity are associated with the formation of exciplexes.

[en] A Zn(II) complex with N,N'-bis(5-bromosalicylidene)ethylenediamine exhibiting intense visible blue luminescence is synthesized. It is found that the zinc complex fluoresces at 293 K in both polycrystalline form and in solutions (λ_max = 440 and 450 nm, respectively); the relative fluorescence quantum yields of the complex are determined in dilute ethanol, dimethylformamide, and dimethylsulfoxide solutions.

No abstract available

[en] The efficient asymmetric hydrosilylation of imines in the presence of polymethylhydrosiloxane has been investigated by screening chiral diamine-zinc complexes. A series of chiral diamine ligands were prepared from optically pure 1,2-diphenyl-1,2-ethanediamine and screened for effectiveness. N-Benzylic substituents were required for high enantioselectivity; ligands with bulky groups or extra coordinating groups such as OH and S lowered the catalytic activity. The level of asymmetric induction was usually in >90% ee range for aromatic imine substrates. A linear correlation between the ee of the ligand and that of the product was observed, indicating the presence of a 1:1 ratio of ligand to metal coordination in the active catalytic complex