Copper(II) Complexes with N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea (L) and a Derivative of L: Synthesis, Structure, and Fluorescent Properties

Abstract

Three copper(II) complexes, [Cu2(OAc)4L2]·2CH3OH (1), [CuBr2L′2(CH3OH)]·CH3OH (2a), and [CuBr2L′2(DMSO)]·0.5CH3OH (2b) {L = N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea and L′ = N‐[10‐(10‐methoxy‐anthronyl)]‐N′‐(3‐pyridyl)urea} have been synthesized by the reaction of L with the corresponding copper(II) salts. Complex 1 shows a dinuclear structure with a conventional “paddlewheel” motif, in which four acetate units bridge the two CuII ions. In complexes 2a and 2b, the anthracenyl ligand L has been converted to an anthronyl derivative L′, and the central metal ion exhibits a distorted square pyramidal arrangement, with two pyridyl nitrogen atoms and two bromide ions defining the basal plane and the apical position is occupied by a solvent molecule (CH3OH in 2a and DMSO in 2b).

Copper(II) Complex of a Urea‐functionalized Pyridyl Ligand: Synthesis, Crystal Structure, and Acetate Binding Properties

“…The copper atom (Cu1) is slightly out of the square plane of oxygen atoms (0.207 Å), which is consistent with the theory that the longer the Cu ··· Cu distance within the dimer, the higher the Cu out‐of‐plane deviation . In complex 1 , the Cu1 ··· Cu1 i distance is 2.6432(11) Å, which falls into the same order of magnitude as described in the literature (2.612–2.713 Å) . Adjacent complex 1 units are held together by the C–H ··· O hydrogen bonds [C4 ··· O1 iii , 3.362(6) Å, C4–H4 ··· O1 iii , 144.5°, Figure c and Table ], forming a hydrogen bond chain structure including paddle‐wheel units.…”

Effect of coordinating (–CN) vs. non-coordinating (–F) substituents in 3-pyridyl urea receptors toward second sphere sulfate recognition: selective crystallisation of CuSO4 from mixtures of competing anions/cations

“…40,41 A number of urea based pyridyl receptors have been constructed to include or bind sulfate ions through second sphere coordination. 26,27,40,[42][43][44][45][46][47][48][49][50][51][52][53][54][55] Recently, we have shown the effect of phenyl vs. pentafluorophenyl substitutions in 3-pyridyl urea towards sulfate recognition. 55 Herein, we demonstrate the effect 4-fluorophenyl (non-coordinating) vs. 4-cyanophenyl (coordinating) substituents in simple 3-pyridyl urea (L 1 and L 2 ; Scheme 1) towards the second sphere recognition of SO…”