Synthesis, characterization, and preliminary fluorescence study of a mixed-ligand bis(dicarbollyl)nickel complex bearing a tryptophan-BODIPY FRET couple

Synthesis and Structure of Methylsulfanyl Derivatives of Nickel Bis(Dicarbollide)

“…− in aqueous solution [22,23] by the reaction of NiCl 2 •6H 2 O with [10-MeS-7,8-C 2 B 9 H 11 ] − in 40% aqueous NaOH, as well as in nonaqueous media, using anhydrous NiCl 2 in tetrahydrofuran [13,22], were unsuccessful. Nevertheless, we were able to synthesize the goal product by using the same approach that was used previously for the synthesis of 6,6'-substituted derivatives of nickel bis(dicarbollide) [11,12,24] is preferred for nickel(III) bis(dicarbollide) [7][8][9][10]. Somewhat later, several such molecular switches were synthesized [11,12]; however, it was found that the difference in energies between the transoid and gauche rotamers in the synthesized nickel(III) complexes are negligibly low (~0.1 kcal/mol) [11].…”

“…Nevertheless, we were able to synthesize the goal product by using the same approach that was used previously for the synthesis of 6,6'-substituted derivatives of nickel bis(dicarbollide) [11,12,24] is preferred for nickel(III) bis(dicarbollide) [7][8][9][10]. Somewhat later, several such molecular switches were synthesized [11,12]; however, it was found that the difference in energies between the transoid and gauche rotamers in the synthesized nickel(III) complexes are negligibly low (~0.1 kcal/mol) [11]. In addition, it was found that nickel(IV) bis(dicarbollide) complexes are unstable in a number of solvents and are easily reduced to the corresponding nickel(III) complexes [13,14].…”

Ferrocene and Transition Metal Bis(Dicarbollides) as Platform for Design of Rotatory Molecular Switches

“…The presence (13 Å < l < 39 Å) or absence ( l > 39 Å) of energy transfer in the designed system provides insight into the conformational changes of nickel bis(dicarbollide) in solution. The fluorescence study revealed FRET transfer between the two fluorophores not only for the Ni(IV) complex, but also (to some extent) for the Ni(III) complex, that can be explained by existence at least part of nickel(III) bis(dicarbollide) in solution in gauche conformation with l < 39 Å [ 65 ].…”

“… Design of nickel bis(dicarbollide) complexes bearing tryptophan and 4,4-difluoro-4-bora-3 a ,4 a -diaza-s-indacene (BODIPY) fluorophore molecules. Reproduced with permission from [ 65 ]. Copyright (2015) Elsevier.…”

The First Nickelacarborane with closo-nido Structure

“…In addition to purely academic interest, a number of them show excellent prospects for practical use. Thus, nickel bis(dicarbollide) and its derivatives [ 4 ] attract interest of researchers due to their potential applications in materials science, including molecular switches [ 5 , 6 , 7 , 8 ], solar cells [ 9 , 10 ] and conductive metal-organic frameworks [ 11 ]. At the same time, the available information on the stability of these complexes is fragmentary and rather contradictory [ 12 , 13 , 14 , 15 ].…”