Jingwei Luo

University of Victoria | UVIC · Department of Chemistry

When constructed out of two identical, dissymmetrical, bidentate ligands, square planar platinum(II) complexes may take the form of two isomers, with either ‘head-to-head’ (HH) or ‘head-to-tail’ (HT) orientations. These two isomers display a different footprint which may impact their respective ability to interact with natural biomolecules. Such a...

Simple particle counting cannot in general be reliably employed to predict the observed architecture as DFT analysis shows that vibrational contributions to entropy dominate and may significantly influence the preferred architecture. However, simple particle counting, which predicts triangles over squares, is seen to be correct here, and DFT confir...

Invited for the cover of this issue is the collaborative team of Anna L. Garden, Sally Brooker and co-workers at the University of Otago (New Zealand), along with collaborators from Victoria and Montreal (Canada). The image depicts the entropic balancing act between 4 triangles and 3 squares, an argument which must be used with caution Read the ful...

Bromobenzyl compounds react selectively with phenols via the Williamson ether synthesis. An imidazolium charge-tagged bromobenzyl compound can be used to reveal phenol impurities in jet fuel by analysis via electrospray ionization mass spectrometry. The complex matrix as revealed by Cold EI GC/MS analysis is reduced to a few simple sets of compound...

Self-assembly of 1:1:2 MII(BF4)2 (M = Zn or Fe), pyrazine-2,5-dicarbaldehyde (1) and 2-(2-aminoethyl)pyridine gave trimetallic triangle architectures rather than the anticipated tetrametallic [2x2] squares. Options for the non-trivial synthesis of 1 are considered, and synthetic details provided for both preferred routes. Rare cyclohelicate triangl...

Rhodium-catalyzed hydrogenation of alkynes was studied under conditions of low concentration of substrate and either one or two equivalents of hydrogen using pressurized sample infusion electrospray ionization mass spectrometry (PSI-ESI-MS). Four sample vials of the same volume but of different diameter enabled the investigation of the effects of s...

Complexation of 1,4-phenylenebis(methylene) diisonicotinate, L1, with cis-protected Pd(II) components, [Pd(L')(NO3 )2 ], in an equimolar ratio yielded binuclear complexes, 1 a-d of [Pd2 (L')2 (L1)2 ](NO3 )4 formulation where L' stands for ethylenediamine (en), tetramethylethylenediamine (tmeda), 2,2'-bipyridine (bpy), and phenanthroline (phen). The...

The cationic rhodium complex [Rh(PcPr3)2(η6-PhF)]+[B{3,5-(CF3)2C6H3}4]− (PcPr3 = triscyclopropylphosphine, PhF = fluorobenzene) was used as a catalyst for the hydrogenation of the charge-tagged alkyne [Ph3P(CH2)4C2H]+[PF6]−. Pressurized sample infusion electrospray ionization mass spectrometry (PSI-ESI-MS) was used to monitor reaction progress. Exp...

A new pyridine ligand based on a T-shaped 2,4,7 trisubstituted benzimidazole framework was synthesized with a 90o angle between the two nitrogen donors. When combined with convergent [Pt(dppp)]2+ corners, eight right angles (four metal and four ligand) combine to form a M4L4 cluster with an unusual folded-cube structure.

The conjugate addition of an alcohol to a butynoate ester using an organophosphine catalyst was monitored using pressurized sample infusion electrospray ionization mass spectrometry (PSI-ESI-MS), together with 31P and 1H NMR spectroscopy. The combination of methods allowed examination of the reaction progress from the perspective of reactants and p...

Continuous monitoring using electrospray ionisation mass spectrometry (ESI-MS) shows that Wilkinson's catalyst hydrogenates a charge-tagged alkyne to the corresponding alkene, and at only a marginally slower rate, to the alkane. No rhodium-containing intermediates were observed during the reaction, consistent with the established mechanism which po...

A method for the direct conversion of arylboronate esters to aryl fluorides under mild conditions with readily available reagents is reported. Tandem reactions have also been developed for the fluorination of arenes and aryl bromides through arylboronate ester intermediates. Mechanistic studies suggest that this fluorination reaction occurs through...

Pressurized sample infusion (PSI) continuously delivers solution from a flask through capillary tubing at a flow rate that makes it suitable as a low internal volume pumping method for electrospray ionization mass spectrometry (ESI-MS). The flow rate can be predicted from the applied pressure by using the Hagen–Poiseuille equation, but variability...

A series of dicobalt hexacarbonyl complexes with charged alkyne ligands were prepared to enable the study of the Pauson–Khand reaction using ESI-MS. The hexacarbonyl complexes can be activated in the gas phase through removal of a CO ligand. The resulting pentacarbonyl ions react readily with alkenes, and no discrimination between alkenes was found...

http://csc2011.cheminst.ca/00000484.htm