Structure, Spectroscopic, Magnetic, Fluorescence, and Thermal Studies of Bis(perchlorate)tetrakis(pyrazole)copper(II)

Abstract

The complex bis(perchlorate)tetrakis(pyrazole)copper(II) has been prepared and characterized by single crystal X-ray analysis, FT-IR, UV-VIS spectroscopy and thermal methods. [Cu(ClO 4 ) 2 (pyzl) 4 ] crystallizes in the monoclinic system, space group C2/c, with a = 14.5186(11), b = 9.9513(7), c = 15.8564(11) Å, β = 115.5290(10) • V = 2067.2(3) Å 3 and z = 4. The molecular and crystal structure are stabilized by inter and intra molecular hydrogen bonds. The complex formation kinetics was studied at 310 nm. The activation parameters of the complex formation kinetics were determined as, H # : 200 kJ/mol, S # : 268 J/K. mol. The FT-IR spectra has been measured and assigned in the range of 4000-400 cm −1 . The Cl-O and N-H stretching vibrations confirms the presence of intramolecular hydrogen bonds. The magnetic moment of the complex was found to be 1.73 BM. The fluorescence quenching of pyrazole by Copper(II) was also studied in methanol.

The effect of anions in the synthesis and structure of pyrazolylamidino copper(ii) complexes

“…In the recrystallization process of 1 , relatively minor amounts of purple crystals, [Cu(pzH) 4 (ClO 4 ) 2 ], 24 were found and confirmed by X-ray diffraction. In a previous report showing the preparation of monomeric and tetranuclear pyrazolylamidino Cu( ii ) complexes in MeOH/MeCN mixed solution, the syntheses conducted at temperatures below 60 °C only afford [Cu(pzH) 4 (NO 3 ) 2 ] or [Cu(pzH) 4 (ClO 4 ) 2 ], and the assumption that higher temperature is required for pzH-RCN coupling on Cu( ii ) ions to occur is made.…”

“…Commercially available chemicals were purchased from Aldrich or Acros and used as received. The complexes [Cu( pzH) 4 (ClO 4 ) 2 ], 24 [Cu( pzH) 4 (NO 3 ) 2 ], 12 and [Cu( pzH) 4 Cl 2 ] 12 were synthesized and recrystallized by following the published procedures. CAUTION: Perchlorate salts are potentially explosive and should only be handled in small quantities.…”

“…A solution of 2 dissolved in 400 μL of CD 3 CN was transferred to the NMR tube and the tube was well-sealed. The spectra were recorded at 0, 2, 4,8,12,24,26,48,72,96,120 and 144 h at 298 K.…”

Chlorine-Decorated Ceria Nanocubes for Facilitating Low-Temperature Cyclohexane Oxidative Dehydrogenation: Unveiling the Decisive Role of Surface Species and Acid Properties

“…The difference lies in the vibration region between 1700 and 800 cm –1 , where the partial bands between 1700 and 1250 cm –1 originate from the C–O stretching vibration in carbonate and formate species, which is formed when ceria is exposed to carbon species. Moreover, additional peaks at 1632 and 932 cm –1 appear after modification, which are attributed to the bending vibrations of the water bands hydrating Cl – ions and symmetrical stretching vibrations of Cl–O, − respectively. That is the evidence for chlorine immersion in ceria nanocrystals.…”