An Efficient Cyan Emission from Copper (II) Complexes with Mixed Organic Conjugate Ligands.
MATERIALS 2022;
15:ma15051719. [PMID:
35268951 PMCID:
PMC8910964 DOI:
10.3390/ma15051719]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/18/2022] [Accepted: 02/20/2022] [Indexed: 01/27/2023]
Abstract
Copper (II) complexes containing mixed ligands were synthesized in dimethyl formamide (DMF). The intense cyan emission at an ambient temperature is observed for solid copper (II) complexes with salicylic acid and a 12% quantum yield with a fluorescent lifetime of approximately 10 ms. Hence, copper (II) complexes with salicylic acid are excellent candidates for photoactive materials. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) reveal that the divalent copper metal centers coordinate with the nitrogen and oxygen lone pairs of conjugate ligands. XPS binding energy trends for core electrons in lower-lying orbitals are similar for all three copper (II) complexes: nitrogen 1s and oxygen 1s binding energies increase relative to those for undiluted ligands, and copper 2p3/2 binding energies decrease relative to that for CuCl2. The thermal behavior of these copper complexes reveals that the thermal stability is characterized by the following pattern: Cu(1,10-phenanthroline)(salicylic acid) > Cu(1,10-phenanthroline)(2,2’-bipyridine) > Cu(1,10-phenanthroline)(1-benzylimidazole)2.
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