Heteroleptic copper(i) complexes bearing functionalized 1H-pyrazole-bipyridine ligands: synthesis, photophysical properties, crystal structures, and applications in halogen sensing

A series of new heteroleptic copper(i) complexes [Cu(NN)(P<^>P)][BF4] (1-6), where N<^>N is a pyrazole-substituted 2,2'-bipyridine (5-(1H-pyrazol-4-yl)-2,2'-bipyridine (5-pzbpy, L-1), 4,4 & PRIME;-di(1H-pyrazol-4-yl)-2,2'-bipyridine (4,4 & PRIME;-pz(2)bpy, L-2), 5,...

Full description

Saved in:
Bibliographic Details
Published inNew journal of chemistry Vol. 47; no. 9; pp. 4374 - 4385
Main Authors Tong, Jin, Zhao, Li-Rong, Zhang, Jin, Wang, Xia-Yan, Yu, Yan-Min, Yu, Shu-Yan
Format Journal Article
LanguageEnglish
Published CAMBRIDGE Royal Soc Chemistry 27.02.2023
Royal Society of Chemistry
Subjects
Chemistry
Chemistry, Multidisciplinary
Copper
Crystal structure
Fluorescence
Hydrogen bonds
Luminous intensity
NMR
Nuclear magnetic resonance
Physical Sciences
Pyrazole
Science & Technology
Titration
Ultraviolet radiation
Online AccessGet full text

Cover

More Information
Summary:A series of new heteroleptic copper(i) complexes [Cu(NN)(P<^>P)][BF4] (1-6), where N<^>N is a pyrazole-substituted 2,2'-bipyridine (5-(1H-pyrazol-4-yl)-2,2'-bipyridine (5-pzbpy, L-1), 4,4 & PRIME;-di(1H-pyrazol-4-yl)-2,2'-bipyridine (4,4 & PRIME;-pz(2)bpy, L-2), 5,5 & PRIME;-di(1H-pyrazol-4-yl)-2,2'-bipyridine (5,5'-pz(2)bpy, L-3), and 3,8-di(1H-pyrazol-4-yl)-1,10-phenanthroline (3,8-pz(2)phen, L-4)) and PP is either oxybis(2,1-phenylene)bis(diphenylphosphane) (POP) or 1,3-bis(diphenylphosphanyl)propane (dppp), were successfully prepared and investigated. The crystal structures of 1, 2, 3 and 6 were determined by single X-ray diffraction. The novel copper(i) complexes 1, 2 and 3 show turn-on emission sensing for halogen ions. The fluorescence enhancement of the copper(i) complexes increases in the order of F- < I- < Br- < Cl-, and the differences in fluorescence intensity could be easily distinguished with the naked eye under UV light illumination. The H-1 NMR titration indicated that the interaction involves hydrogen-bond formation between the halide (Cl-, Br- and I-) and the acidic H of the pyrazole group, with N-H deprotonation occurring at increasing F- concentrations. The result was further confirmed by carrying out theoretical calculations.
ISSN:1144-0546
1369-9261
DOI:10.1039/d2nj05408f