Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Effects of a derivative thiazoline/thiazolidine azine ligand and its cadmium complexes on phagocytic activity by human neutrophils

“…The analysis of bond lengths N(3)-C(6) and C(6)-N(4) in complexes 1 and 2 shows that the organic ligand presents an amino-2-thiazoline form instead of the iminothiazolidine one observed in ATHTd in the free state [24]. This fact does not allow the coordination of two azine nitrogen atoms from ATHTd, differently to what it happens in other azine complexes [50] where azine ligand bridges two metal ions. Another difference in complexes with respect to the structure of free ligand ATHTd is due to the different degree of rotation of the thiazoline rings around the C(1)-C(4) bond, which permits the coordination through thiazoline nitrogen atom N(1) [torsion angle S(1)-C(1)-C(4)-N(2) = À179.7°in 1, 172.4°in 2, À2.2°in ATHTd].…”

Chirality Transfer through Helical Motifs in Coordination Compounds

“…High‐dimensional homochiral structures could also be assembled by the helical fragments and adducts as initial components. Chen et al reported a 2D network built from hydrogen bonds between the connecting water clusters and the helicates 34. The initial fragment for the assembly is a binuclear Cd II helicate with two spiral‐like N , N ′‐bis(picolinamide)azine ligands (L 2 ) coordinated to the two Cd II centers.…”

Tetraaquabis(5-carboxy-2-nitrobenzoato-κO)manganese(II) dihydrate: a metal–water chain complex containing cyclic water tetramers

“…The average OÁ Á ÁO distance is 2.99 A Ê . This distance is signi®cantly longer than the distance of 2.78 A Ê estimated in the water tetramer of (D 2 O) 4 in the gas phase (Cruzan et al, 1996), and longer than in other tetrameric clusters reported previously (2.77±2.94 A Ê ; Supriya & Das, 2003;Long et al, 2004;Zuhayra et al, 2006;Tao et al, 2004;Ye et al, 2005). However, it is shorter than that observed in 1,4,7,10-tetraazacyclododecane trihydrate (3.004 A Ê ; Pal et al, 2003).…”