Counter-ligand control of the electronic structure in dinuclear copper-tetrakisguanidine complexes.
Dalton Trans
; 44(44): 19111-25, 2015 Nov 28.
Article
en En
| MEDLINE
| ID: mdl-26477859
ABSTRACT
The redox-active GFA (Guanidino-Functionalized Aromatic compound) 1,4,5,8-tetrakis(tetramethylguanidino)-naphthalene (6) is used to synthesize new dinuclear copper complexes of the formula [6(CuX2)2] with different electronic structures. With X = OAc, a dinuclear Cu(II) complex of the neutral GFA is obtained (electronic structure [Cu(II)-GFA-Cu(II)], two unpaired electrons), and with X = Br a diamagnetic dinuclear Cu(I) complex of the dicationic GFA (electronic structure [Cu(I)-GFA(2+)-Cu(I)], closed-shell singlet state). The different electronic structures lead to significant differences in the optical, structural and magnetic properties of the complexes. Furthermore, the complex [6(CuI)2](2+) (electronic structure [Cu(I)-GFA(2+)-Cu(I)], closed-shell singlet state) is synthesized by reaction of 6(2+) with two equivalents of CuI. Slow decomposition of this complex in solution leads to the fluorescent dye 2,7-bis(dimethylamino)-1,3,6,8-tetraazapyrene. In an improved synthesis of this tetraazapyrene, 6 is reacted with CuBr in the presence of dioxygen. Quantum chemical calculations show that the addition of counter-ligands to the trigonal planar Cu(I) atoms of [6(CuI)2](2+) favors or disfavors one of the electronic structures, depending on the nature of the counter-ligand.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Cobre
/
Guanidina
Idioma:
En
Revista:
Dalton Trans
Asunto de la revista:
QUIMICA
Año:
2015
Tipo del documento:
Article
País de afiliación:
Alemania