Secondary Structures in Inorganic Helicates of an Octadentate Phenanthroline‐Type Schiff Base Ligand

Abstract

Abstract:To analyze the contribution of supramolecular interactions to helical architectures and to investigate whether ligand folding can be induced by only protons in a similar fashion in the absence of metal ions, a new 1,10-phenanthroline (phen)-based extended ligand,

Polymorphic Copper Iodide Anions: Luminescence Thermochromism and Mechanochromism of (PPh4)2[Cu2I4]

“…33 Another binuclear anion is [Cu2I4] 2which has been encountered in several associations with different organic and inorganic cations. 34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66 The photophysical properties of these compounds have been rarely characterized, [Cu2I4] 2being simply treated as an inorganic counter-anion and not as an emissive species by itself. In particular, with the tetraphenylphosphonium cation, the polymorphic structure of (PPh4)2[Cu2I4] has been reported but no photophysical characterization has been investigated.…”

Structural and NMR Spectroscopic Investigations of CuI, CuII, NiII, ZnII and FeII Complexes of 2, 9‐Di‐(Benzothiazolino)‐1,10‐Phenanthroline

“…2 is one of a few examples of helicates containing 1,2‐bifunctional N‐ donor ligands with phen like rigid geometries which do not act as chelating groups towards Cu I ions. Other examples are the copper(I) complexes of Schiff base ligands derived from Phen and aromatic primary amines such as 2‐methylmercaptoaniline or 4‐flouroaniline or 8‐aminoquinoline . In the dicopper helicate [Cu 2 (C 12 H 6 N 2 (CHNC 6 H 4 SMe) 2 ) 2 ] 2+ (Scheme , Figure ), the torsion angles of the N−C‐C−N fragments (9.4° and 10.4°) are less than those of 3 and the Cu I ….Cu I distance is less (2.695(1) Å) …”

“…With the exclusion of the major and minor grooves concept, this architecture along with the structural view down the helical axis (Figure a and SI Figures and in supporting information) are visualised as topological models of B‐DNA which is constituted by two anti‐parallel polynucleotide ribbons with phosphate ions and pairing bases in the center through H‐bonding and stacking interactions. A range of other ligand types are known in the literature which form complexes of a similar type of architecture on metal ion interactions (Figure ) …”

“…Aromatic π‐stacking interactions (∼3.63 Å) are also present in these systems. It is of interest to investigate the coordination properties of these ligands with other metal ions or interactions with protons in particular viz., whether two ligands can be folded similarly by H‐bonding in the absence of metal ions . Results upto date indicate that the 2,9‐disubstituted 1,10‐phenanthroline (phen) type Schiff base is ambivalent towards two different metal ions under different experimental conditions.…”

“…The ligand can be bridging‐binucleating or fully chelating and mono‐nucleating with additional donor sites. The structural chemistry of the copper(I) helicates of substituted phen ligands has recently gained momentum in the areas of self‐assembly and supramolecular chemistry . The self‐assembly instructions of subcomponent building blocks serve as subroutines to guide the generation of a more complexed superstructures, viz., molecular wires .…”