resumo
A series of new copper(II)-azido complexes of 1D polymeric chains of [Cu(L 1 )( mu 1,3 -N 3 )] n ( 1 ) and [Cu(L 2 )( mu 1,3 - N 3 )] n ( 2 ), and binuclear [Cu(L 3 )( mu 1,1 -N 3 )] 2 ( 3 ) [HL 1 = N -butyl-N-(5-bromosalcylidine)ethane-1,2-diamine, HL 2 = N -butyl-N-(5-chlorosalcylidine)ethane-1,2-diamine, HL 3 = N -butyl- N -(salcylidine)ethane-1,2-diamine] have been synthesized and characterized. Characterizations of 1 -3 have been accomplished by usual physico-chemical techniques such as elemental analysis, FTIR, UV - vis and single crystal X-ray diffraction studies. X-ray diffraction analyses of 1 and 2 reveal that the monomeric units of 1D polymers are interconnected via the mu 1,3 -azido bridging. The coordination geometry around the copper(II) centers in 1 and 2 can be best described as distorted square pyramidal environments. Complex 3 shows a centrosymmetric structure with two copper(II) centers that are held together by mu 1,1 -azido bridging in a distorted square pyramidal environment. In the electrical studies of 1 -3 , both direct current (dc) and alternating current (ac) analyses have been carried out based on the metalcomplex (1/2/3) -metal (M -S -M) structures. The sheet resistance of the deposited films and the metal-complex contact resistance are estimated by employing transfer length method (TLM) measurements. The dark currentvoltage characteristics of Al-complex (1/2/3) -Al structures are analyzed by considering dual back-to-back Schottky barrier diode structure. The voltage variations of the device current under illumination (400 - 700 nm) clearly demonstrate the photo-sensitivity of these materials. The catalytic activities of 1 -3 have been investigated towards aerial oxidation of 3,5-di-tert-butylcatechol. All three complexes exhibit potential catalytic effectiveness towards oxidation of 3,5-di- tert -butylcatechol (3,5-DTBC) to 3,5-di- tert -butyl- o -quinone (3,5-DTBQ) with turnover numbers 14.76, 33.92 and 81.02 h -1 for 1, 2 and 3 , respectively.
palavras-chave
TRIDENTATE SCHIFF-BASES; X-RAY-STRUCTURE; DINUCLEAR COPPER(II); MAGNETIC-PROPERTIES; BINUCLEAR COPPER(II); CRYSTAL-STRUCTURE; COMPLEXES; LIGAND; OXIDASE; SPECTROSCOPY
categoria
Chemistry
autores
Roy, I; Branda, P; Majumder, A; Bera, M; Banerjee, A; Saha, S
nossos autores
Paula Cristina Ferreira da Silva Brandão
Investigador AuxiliarProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
The financial support from UGC [Sanction no. F. 38-5/2009 (SR) ] and DST [Sanction no. SR/FT/CS-060/2009] , New Delhi to S.S. is gratefully acknowledged. This work was supported by the infrastructure provided by the Department of Chemistry and Electronic Science, Acharya Prafulla Chandra College under the DST -FIST scheme (Sanction order: SR/FST/College-008 dated 15/02/2012) . AB is thankful to Dr. Nirmalendu Sarkar (Principal, Katwa College) , for his help to carry out this work. Paula Brandao gratefully acknowledges the financial support of this work by the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC) .