192226-54-3Relevant academic research and scientific papers
Modifying the steric and electronic character within Re(I)-phenanthroline complexes for electrocatalytic CO2 reduction
Neyhouse, Bertrand J.,White, Travis A.
, p. 49 - 57 (2018)
We have synthesized and characterized a series of fac-[Re(R2phen)(CO)3Cl] complexes (R2phen = 2,9-disubstituted-1,10-phenanthroline) that function as electrocatalysts for the reduction of CO2 to CO. The 2,9-disubstituted phenanthroline ligands contain proton (phen), methyl (2,9-Me2phen), trimethylphenyl (Mes2phen), or trimethoxyphenyl ((2,4,6-tmp)2phen and (3,4,5-tmp)2phen) groups as steric and electronic modifiers to provide insight into factors impacting catalytic activity. Cyclic voltammograms (CVs) recorded in CO2-saturated CH3CN or DMF solutions reveal that following two-electron reduction and chloride dissociation to form the active [Re(R2phen)(CO)3]? intermediate, current enhancement indicative of CO2 reduction to CO was observed and confirmed by controlled potential electrolysis (CPE). Using current enhancement values (icat/ip, where icat and ip are the current response under CO2 and N2, respectively) to estimate catalytic activity, it was observed that catalysts with more cathodic ReI/0 potentials displayed greater activity, in accord with an electronic effect driving catalysis. Interestingly, the trimethoxyphenyl-substituted complexes Re((2,4,6-tmp)2phen) and Re((3,4,5-tmp)2phen) showed different degrees of activity in DMF (icat/ip = 14.8 and 6.0, respectively) and CH3CN (icat/ip = 8.5 and 7.7, respectively). These results suggest that while electronics dominate the observed catalytic activity within this fac-[Re(R2phen)(CO)3Cl] architecture, factors such as sterics and solvent play an important role as well.
Strategies for tuning the catalytic activity of zinc complexes in the solvent-free coupling reaction of CO2 and cyclohexene oxide
Biagini, Paolo,Boggioni, Laura,Colombo, Alessia,Cozzolino, Mariachiara,Dragonetti, Claudia,Fagnani, Francesco,Flamigni, Agnese,Losio, Simona,Matozzo, Paola,Perego, Carlo,Po, Riccardo,Roberto, Dominique
, (2021/12/20)
The catalytic activity of various zinc(II) complexes bearing a chelating nitrogen-donor ligand and different ancillary ligands (Cl, acetate, triflate) is investigated for the solvent-free coupling reaction of cyclohexene oxide and CO2. The effect of a co-catalyst is also studied. Whereas the investigated zinc(II) complexes with chloride or acetate as ancillary ligand are inactive, those with triflate are active, allowing the selective formation of polyether or cyclic carbonate controlled by the presence of a suitable amount of [PPN]Cl.
Surface immobilized copper(i) diimine photosensitizers as molecular probes for elucidating the effects of confinement at interfaces for solar energy conversion
Eberhart, Michael S.,Phelan, Brian T.,Niklas, Jens,Sprague-Klein, Emily A.,Kaphan, David M.,Gosztola, David J.,Chen, Lin X.,Tiede, David M.,Poluektov, Oleg G.,Mulfort, Karen L.
supporting information, p. 12130 - 12133 (2020/10/21)
Heteroleptic copper(i) bis(phenanthroline) complexes with surface anchoring carboxylate groups have been synthesized and immobilized on nanoporous metal oxide substrates. The species investigated are responsive to the external environment and this work provides a new strategy to control charge transfer processes for efficient solar energy conversion.
Synthesis, structure, ultrafast kinetics, and light-induced dynamics of CuHETPHEN chromophores
Kohler, Lars,Hayes, Dugan,Hong, Jiyun,Carter, Tyler J.,Shelby, Megan L.,Fransted, Kelly A.,Chen, Lin X.,Mulfort, Karen L.
, p. 9871 - 9883 (2016/07/06)
Five heteroleptic Cu(i)bis(phenanthroline) chromophores with distinct variation in the steric bulk at the 2,9-phenanthroline position were synthesized using the HETPHEN method, and their ground and excited state properties are described. Analysis of the crystal structures reveals a significant distortion from tetrahedral geometry around the Cu(i) centre which is attributed to favourable aromatic interactions between the two phenanthroline ligands. Ultrafast and nanosecond transient optical spectroscopies reveal that the excited state lifetime can be tuned across two orders of magnitude up to 74 nanoseconds in acetonitrile by changing the 2,9-substituent from hydrogen to sec-butyl. X-ray transient absorption spectroscopy at the Cu K-edge confirmed Cu(i) oxidation to Cu(ii) and revealed a decrease of the Cu-N bond lengths in the excited state. The ground and excited state characterization presented here will guide the integration of CuHETPHEN chromophores into complex electron donor-acceptor architectures.
Synthesis and self-assembly of a rigid exotopic bisphenanthroline macrocycle: Surface patterning and a supramolecular nanobasket
Kalsani, Venkateshwarlu,Ammon, Horst,Jaeckel, Frank,Rabe, Juergen P.,Schmittel, Michael
, p. 5481 - 5492 (2007/10/03)
The synthesis and characterisation of a rigid nanoscale macrocycle with two exotopic phenanthroline binding sites is reported. Scanning tunnelling microscopy (STM) at the solid-liquid interface reveals the formation of highly ordered monolayers of macrocy
Synthesis of unsymmetrical 2,8- and 2,9-dihalo-1,10-phenanthrolines and derivatives
Toyota, Shinji,Woods, Craig R.,Benaglia, Maurizio,Siegel, Jay S.
, p. 2697 - 2700 (2007/10/03)
A general method for the preparation of the unsymmetrical 2,8- and 2,9- dihalophenanthrolines is presented. The use of these halophenanthrolines as synthetic substrates in the Suzuki and Sonogashira/Castro-Stevens palladium catalyzed chemistry is exemplifed. The derivatized phenanthrolines are seen as key building blocks for the design and construction of topologically complex polynuclear metal coordination complexes.
