Synthesis, Structure, Property, and Dinuclear Cu(II) Complexation of Tetraoxacalix[2]arene[2]phenanthrolines

Abstract

A number of novel tetraoxacalix[2]­arene[2]­phenanthrolines 7–11 containing phenanthroline and diverse aromatic linkages were conveniently synthesized by a one-pot protocol between a series of dihydroxy arenes and 1,10-phenanthroline derivatives. Single-crystal diffraction analysis revealed that the resulting macrocycles possess diverse conformational and cavity structures which are regulated by the different aromatic linkages. In line with the length of the aromatic linkages, the distance between the two phenanthroline moieties (d N–N) gradually increases from 6.92 to 13.30 Å, respectively. The physicochemical properties of these macrocyclic compounds were investigated by spectroscopic, CV, and DPV measurements. Owing to the coordination ability of the phenanthroline moieties and the tunable conformational structure, the macrocyclic hosts can form distinct dinuclear complexation with Cu2+. Typically, with a short aromatic linkage the 7b–2Cu­(II) complex gives an O-bridged dicopper structure, while with long linkage the 11b–2Cu­(II) complex possesses two discrete copper centers. The spectroscopic structure and the redox property of the dicopper complexes were investigated by XPS, CV, and DPV techniques. This work hence provides a platform to access biomimetic copper-containing small-molecule models with well-defined structures.

Synthesis of substituted (N,C) and (N,C,C) Au(iii) complexes: the influence of sterics and electronics on cyclometalation reactions

“…84 The N1-C1-O5 angle in 2m-Au(OAc F ) 2 is 114.51(18)°, being slightly smaller than the corresponding N-C-O(alkoxy) angles in reported crystal structures of non-coordinated pyridines, bipyridines or phenanthrolines with alkoxy substituents α to nitrogen (typically around 120°). 40,[84][85][86][87][88] The angle is similar to the N-C-O(alkoxy) angle in (N,C) Au(III) and Pd(II) complexes derived from 6,6′-dimethoxy-2,2′-bipyridine reported by Cinellu and co-workers. 40,84 The relatively small N-C-O(alkoxy) angle in 2m-Au(OAc F ) 2 , together with a Au1-O5 distance of 3.13 Å may hint at a weak interaction between the gold centre and the oxygen atom in the methoxy group.…”

Fifty Shades of Phenanthroline: Synthesis Strategies to Functionalize 1,10-Phenanthroline in All Positions

“…First, the reduction of the diketone in the corresponding diol is performed. Several reductants have been used to achieve this reaction (dithionite in a THF/water mixture, − sodium in DMF, or hydrazine sulfate in water). Save the latter case, the diol is usually not isolated and reacted directly as nucleophile with alkyl halides or tosylates in the presence of a base (Cs 2 CO 3 or KOH) to yield the target O-alkylated compound (Scheme ).…”

“…Regarding reactions involving the C–halogen bond in 1144 , 1145 , and derivatives thereof, to date two kinds of reactions have been reported: catalyzed cross-coupling reactions ,,, and aromatic nucleophilic substitutions. ,,,,,, …”

“…Regarding reactions involving the C−halogen bond in 1144, 1145, and derivatives thereof, to date two kinds of reactions have been reported: catalyzed cross-coupling reactions 974,1090,1095,1102 and aromatic nucleophilic substitutions. 916,1073,1085,1089,1096,1103,1104 Cross-coupling reactions have rarely been performed directly on 1144 or 1145. The sole example reported in the literature is depicted in Scheme 252 and consists of a Suzuki crosscoupling involving 1145 and boronic pinacol ester 1207 in classical conditions.…”

First 24-Membered Macrocyclic 1,10-Phenanthroline-2,9-Diamides—An Efficient Switch from Acidic to Alkaline Extraction of f-Elements

“…A number of macrocycles containing a fragment of 1,10-phenanthroline have been described. For example, ligands of the “Phen-O-Ar-” type ( Figure 1 ) have been studied as selective complexing agents for copper ions [ 24 , 25 ].…”