301ChemInform Abstract The title diphosphine (II) is obtained as shown. Its 1:1 molar reaction with PdCl2(NCPh)2 leads to the mononuclear cis-complex (III). Substitution of the 2-(diphenylphosphino)pyridine ligands in the binuclear complex (IV) with one or two equiv. of the diphosphine yields the diphosphine complexes (V) and (VIa) (X: Cl). By metathetic reactions the last is converted into its derivatives (VIa) (X: Br,I, NCO). The analogue (VIb) with two different diphosphines are obtained from (V). Of the dinuclear Pd2Cl2 species, only (VIb) reacts with CO in solution to form reversibly the A-frame complex (VII). Molecular and crystal structures of the mononuclear complex (III) (space group P1, Z=4), and of the dinuclear complex (VIa) (X: Cl; Fdd2, Z=16) are determined by X-ray analysis. The last is onlyobtained in its anti-form.
A macrocyclic hexanuclear iron(III) 18-metallacrown-6 complex, [Fe 6 (C 9 H 6 BrN 2 O 3 ) 6 (CH 3 OH) 4 (H 2 O) 2 ] Á 7CH 3 OH Á 4H 2 O, has been prepared using a trianionic pentadentate ligand N-acetyl-5-bromosalicylhydrazidate, abshz 3-, and characterized by X-ray diffraction. The crystal structure contains a neutral 18-membered metallacrown ring consisting of six Fe(III) and six abshz 3-ligands. The 18-membered metallacrown ring is formed by combination of six structural moieties, [Fe(III)-N-N]. Due to meridional coordination of ligand to Fe 3þ , the ligand enforces the stereochemistry of the Fe 3þ ions as a propeller configuration with alternating D/L forms. Methanol and water are linked with Fe1, Fe1A, Fe,3 and Fe3A. The ratios of methanol to water are 0.76 : 0.24 for Fe1 and Fe1A, and 0.30 : 0.70 for Fe3 and Fe3A, which results in four component crystals of metallacrown rings with ratio of 0.168 : 0.072 : 0.532 : 0.228. Antibacterial screening data showed that the iron metallacrown has moderate antimicrobial activity against Bacillus subtilis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.