News from the lab

Congrats to our 2017 graduates!!!

Stephanie Bellinger PhD

Raymond E. Borg MS

Veronika Belkina BS

...a great year for Rochfordlab graduates. Hearty congrats to Stephanie, Ray and Veronika !!!

JACS paper on proton coupled CO2 reduction published

A major achievement by Tue, Meaghan, Bani and Remya. Our study of using a pendant base to enhance electrocatalytic CO2 reduction properties for Mn polypyridyl catalysts has been accepted in the Journal of the American Chemical Society . Thanks to Dr. Mehmed Z. Ertem and Dr. David C. Grills at Brookhaven National Laboratory for their invaluable contribution !!!

Chem Eur J DSSC paper published as cover article

Tue, Nick and Sashari's DSSC study "Engineering of ruthenium(II) oxy- and carboxyamido-quinolate non-innocent ligand photosensitizers for dye sensitized solar cells" has been published in Chemistry - A European Journal as a cover article. Another great addition to our ruthenium catalogue !!!

Organometallics paper published

A series of nickel complexes with potentially redox active bis(aldimino)pyridine ligands [NNN] ([NNN] = 1,1′-(pyridine-2,6-diyl)bis(N-arylmethanimine), where aryl = 2,6-diisopropylphenyl, mesityl, 4-methoxyphenyl, 4-trifluoromethylphenyl, and 3,5-bis(trifluoromethyl)phenyl) were synthesized, and their properties and reactivities were investigated as a function of the overall oxidation state of the system. (Ni[NNN])2+ complexes of ligands featuring bulky electron-rich substituents (1a-Br2 and 1b-Br2, [NNN] = 1,1′-(pyridine-2,6-diyl)bis(N-(2,6-diisopropylphenyl)methanimine) and 1,1′-(pyridine-2,6-diyl)bis(N-mesitylmethanimine), respectively) demonstrated five electrochemical reduction events, the first three of which were quasi-reversible. In contrast, only two quasi-reversible reductions were observed for the less bulky and electron-deficient N-aryl substituents 4-(trifluoromethyl)phenyl and 3,5-bis(trifluoromethyl)phenyl. Chemical reduction of 1a-Br2 and 1b-Br2 with 1 equiv of KC8 or CoCp*2 forms (Ni[NNN])+ complexes of the general formula Ni[NNN]Br (2a-Br and 2b-Br). Structural, spectroscopic, and theoretical studies reveal that these complexes feature significant unpaired spin density on the metal, consistent with “nickel(I)” character. This behavior is in contrast with previously reported bis(ketimino)pyridine systems, in which at the (Ni[NNN])+ state the unpaired electron resided exclusively in the ligand. Further reduction forms a series of (Ni[NNN])0 complexes, in which all of the potentially tridentate [NNN] ligands bind via only one iminopyridine unit; the second arm is left unbound in most complexes. Variable temperature NMR spectroscopy demonstrates that bound and unbound arms exchange via a postulated tridentate intermediate. Electrochemical reduction, via three sequential one-electron reductions, of 1a-Br2 and 1b-Br2 in the presence of CO2/H+ forms an active catalyst for H2 evolution at a glassy-carbon electrode surface, again emphasizing the unique redox chemistry of the bulky bis(aldimino)pyridine nickel complexes.

Organometallics, 2017, 36 (3), pp 582–593
DOI: 10.1021/acs.organomet.6b00793

Jan 18th 2017 - Stephanies PhD defense

Congratulations to Stephanie on defending her PhD dissertation "Photophysical & photoacoustic properties of electron rich & pi-extended quadrupolar curcuminoid dyes". A fantastic start to 2017 !

We’re hiring!

The Rochford Research Group is currently looking for highly enthusiastic Ph.D. candidates with a strong interest in inorganic and physical chemistry. For further information please contact Prof. Rochford.