TY - JOUR
T1 - Structural diversity in heteroleptic dipyrrinato copper(II) complexes
AU - Gupta, Rakesh Kumar
AU - Pandey, Rampal
AU - Kumar, Amit
AU - Ramanujachary, K. V.
AU - Lofland, Samuel E.
AU - Pandey, Daya Shankar
N1 - Funding Information:
The authors thank to the Department of Science and Technology (DST), New Delhi, India for financial assistance through the Scheme (SR/S1/IC/-25/2011), and Council of Scientific and Industrial Research (CSIR) New Delhi, India for the award of Junior Research Fellowship to RKG (No. 09/013(0210)/2009-EMR-I). We are also thankful to the Head, Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi (U.P.) India for extending laboratory facilities, Prof. S Natarajan, Indian Institute of Science, Bangalore, India for providing XPS data, Prof. S. Bhattacharya, Jadavpur University Kolkata, Indian Institute of Technology, Powai, Mumbai and Prof. Q. Xu National Institute of Advanced Industrial Science and Technology (AIST), Osaka, Japan for extending single crystal X-Ray facility.
PY - 2014
Y1 - 2014
N2 - Synthesis and characterization of the heteroleptic dipyrrinato complexes [Cu2(2-pcdpm)2(acac)2] (1), [Cu 2(2-pcdpm)2(hfacac)2] (2), [Cu 3(4-OHdpm)2(acac)4] (3), [Cu 3(4-OHdpm)2(hfacac)4] (4), [Cu 2(3-OHdpm)(acac)3] (5), [Cu2(3-OHdpm)(hfacac) 3] (6), [Cu(2-OHdpm)(acac)] (7) and [Cu(2-OHdpm)(hfacac)] (8) (acac = acetylacetone; hfacac = hexafluoroacetylacetone; 2-pcdpm = 4-(2-methoxypyridyl) phenyldipyrromethene; 3-pcdpm = 4-(3-methoxypyridyl)phenyldipyrromethene; 4-pcdpm = 4-(4-methoxypyridyl)phenyldipyrromethene; 4-/3-/2-OHdpm = 4-/3-/(2-hydroxyphenyl)dipyrromethene) have been described. The complexes 1-8 have been characterized by elemental analyses, ESI-MS, IR, UV-Vis, EPR and electrochemical (CV and DPV) studies. Electronic absorption spectra of 1-8 clearly suggested that position of the absorption bands depend on the nuclearity and coordination geometry about the copper(II) centres. Structures of 1, 2, 3 and 7 have been determined by X-ray single crystal analyses. The spectral and structural studies revealed that copper(II) in 1 and 2 adopted square pyramidal geometry, whereas in 7 a square planar geometry. On the other hand in trinuclear complex 3 one copper(II) adopted square planar, while other two square pyramidal geometry. In their cyclic voltammograms, 1-6 exhibited an irreversible oxidation and two reduction waves whereas 7 and 8 displayed one oxidation and reduction wave. Variable temperature magnetic susceptibility measurements suggested paramagnetic nature of the complexes 1-3. The X-ray photoelectron spectroscopic (XPS) studies indicated that copper(II) centres in complex 3 are present in two different coordination environments. Room temperature EPR studies on 1-8 (g|| > g∥ > 2.003) suggested a typical d9 copper(II) with unpaired electron lying in a d x2-y2 orbital.
AB - Synthesis and characterization of the heteroleptic dipyrrinato complexes [Cu2(2-pcdpm)2(acac)2] (1), [Cu 2(2-pcdpm)2(hfacac)2] (2), [Cu 3(4-OHdpm)2(acac)4] (3), [Cu 3(4-OHdpm)2(hfacac)4] (4), [Cu 2(3-OHdpm)(acac)3] (5), [Cu2(3-OHdpm)(hfacac) 3] (6), [Cu(2-OHdpm)(acac)] (7) and [Cu(2-OHdpm)(hfacac)] (8) (acac = acetylacetone; hfacac = hexafluoroacetylacetone; 2-pcdpm = 4-(2-methoxypyridyl) phenyldipyrromethene; 3-pcdpm = 4-(3-methoxypyridyl)phenyldipyrromethene; 4-pcdpm = 4-(4-methoxypyridyl)phenyldipyrromethene; 4-/3-/2-OHdpm = 4-/3-/(2-hydroxyphenyl)dipyrromethene) have been described. The complexes 1-8 have been characterized by elemental analyses, ESI-MS, IR, UV-Vis, EPR and electrochemical (CV and DPV) studies. Electronic absorption spectra of 1-8 clearly suggested that position of the absorption bands depend on the nuclearity and coordination geometry about the copper(II) centres. Structures of 1, 2, 3 and 7 have been determined by X-ray single crystal analyses. The spectral and structural studies revealed that copper(II) in 1 and 2 adopted square pyramidal geometry, whereas in 7 a square planar geometry. On the other hand in trinuclear complex 3 one copper(II) adopted square planar, while other two square pyramidal geometry. In their cyclic voltammograms, 1-6 exhibited an irreversible oxidation and two reduction waves whereas 7 and 8 displayed one oxidation and reduction wave. Variable temperature magnetic susceptibility measurements suggested paramagnetic nature of the complexes 1-3. The X-ray photoelectron spectroscopic (XPS) studies indicated that copper(II) centres in complex 3 are present in two different coordination environments. Room temperature EPR studies on 1-8 (g|| > g∥ > 2.003) suggested a typical d9 copper(II) with unpaired electron lying in a d x2-y2 orbital.
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U2 - 10.1016/j.ica.2013.09.044
DO - 10.1016/j.ica.2013.09.044
M3 - Article
AN - SCOPUS:84887982533
VL - 409
SP - 518
EP - 527
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
SN - 0020-1693
IS - PART B
ER -