Interconversion and ligand dependence in mononuclear and dinuclear cobalt(II) helicate complexes of 2,2′: 6′,2″: 6″,2‴:6‴,2â�—-quinquepyridines; crystal and molecular structure of aqua(methanol)[4′,4‴-bis(4-chlorophenyl)-2,2′:6′,2″:6″,2‴:6‴,2â�—-quinquepyridine]cobalt(II) bis(hexafluorophosphate)

Abstract

Interconversion and Ligand Dependence in Mononuclear and Dinuclear Cobalt(l1) HelicateComplexes of 2,2' : 6',2" : 6",2"' : 6"',2""-Quinquepyridines; Crystal and Molecular Structure of Aqua(methanol)[4',4'"-bis(4-chlorophenyl)-2,2' : 6',2" : 6",2"' : 6"',2'"'quinquepyridine]cobaIt(ii) Bis(hexaf1uorophosphate)

Helicates as Versatile Supramolecular Complexes

“…An abundant literature reports the formation of single-stranded mononuclear helical complexes resulting from the reactions of acyclic receptors with alkali, alkaline earth, and transition metal ions. , Although mononuclear complexes are not considered in our definition of helicates (see section I), some single-stranded mononuclear helical complexes are important precursors of double-stranded helicates − and merit further comments.…”

“…The large silver(I) cation (1.09 Å) 75 almost fits the cavity produced by the cisoid arrangement of the five pyridine rings leading to a slight helical twisting of the strand in the crystal structure of [Ag( 7 )] + . The X-ray crystal structures of [Co( 21 )Cl 2 ], [Co( 26 )(CH 3 OH)(OH 2 )](PF 6 ) 2 , , and [Re( 7 )Cl 2 ]ClO 4 76 show the quinquepyridine strand acting as a pentadentate ligand and forming a more pronounced shallow helical twist about the equatorial plane of a pentagonal bipyramidal seven-coordinate metallic center as a result of the smaller size of Co(II) and Re(III) metal ions (Figure ). The two axial coordination sites are occupied by solvent molecules 61,62 or chloride anions .…”

Crystal structure, luminescence properties and biological studies of a novel polymeric cadmiumII compound: [Cd(Clphtpy)(NCS)(NO3)]n

“…The synthesis of tpy derivatives has been extensively developed by Constable's group and varieties of substituted tpy compounds have been reported [26]. However, the coordination chemistry of 4 -(4-chlorophenyl)-2,2 :6 ,2 -terpyridine (Clphtpy) has been less-well studied [27][28][29][30]. We have recently reported structural characterization of Cd(II) complexes of Cltpy [31,32] and Mephtpy [33] ligands.…”

Modulation of a Supramolecular Bowl and Pot by Changing Solvent Systems and/or Metal/Ligand Ratios

“…Synthesis and characterization of a self‐assembled supramolecular pot 4 : To construct the supramolecular pot 4 by the incorporation of the third and fourth Pd II ions, we attempted to change the solvent system by adding methanol 19. Gentle heating with gradual addition of methanol to an aqueous solution of 3 a and two equivalents of [Pd(en)(NO 3 ) 2 ] resulted in a slow increase in intensity of a new set of 1 H NMR peaks (Figure 5).…”