Browsing Chemistry Faculty Research, Publications and Presentations by Title
Now showing items 69-88 of 171
-
Investigation of factors affecting crystallization of cyclopentane clathrate hydrate
We report the results of systematic investigations of the influence of thermal history and other factors on crystallization of a model clathrate hydrate (cyclopentane hydrate) studied as water-in-oil and oil-in-water ... -
Investigations into the nucleophilic meso-substitution of F-BODIPYs and improvements to the synthesis of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene.
A series of three F-BODIPYs, with varying levels of steric crowding about the meso-position were selected to investigate nucleophilic meso-substitution of F-BODIPYs. The synthesis of one of these F-BODIPYs, 4,4-difluor ... -
Investigations regarding the utility of prodigiosenes to treat leukemia
Prodigiosenes, possessing a 4-methoxypyrrolyldipyrrin skeleton, are known for their anti-cancer activity. Structural modification of the C-ring resulted in a series of prodigiosenes that displayed promising activity against ... -
Isolation and characterization of a novel tetrahydro-[2,2 ']bipyrrolyl dimer as an impurity from a Knorr reaction
A novel dimer, tetraethyl 2,2',3,3'-tetramethyl-1,1',2,2'-tetrahydro-4H,4'H-2,2'-bipyrrolyi-5,5,5',5'-tetracarboxylate, has been isolated as an impurity (0.4% yield) from a Knorr reaction for the synthesis of ... -
Low thermal conductivity of the negative thermal expansion material, HfMo2O8
The thermal conductivity of the cubic polymorph of hafnium molybdate, HfMo2O8, was determined over the temperature range of 2-400 K. The values of thermal conductivity were low (0.64 +/- 0.15 W m(-1) K-1 at T=300 K for a ... -
Measuring the Geometric Component of the Transition-Probability in a 2-Level System
We describe the measurement of a component of the nonadiabatic transition probability in a two-level system that depends only on the path through parameter space followed by the Hamiltonian, and not on how fast the path ... -
Mechanical–Structural Investigation of Ion-Exchanged Lithium Silicate Glass using Micro-Raman Spectroscopy
Micro-Raman spectroscopy was used to determine the structural modifications occurring in a simple ion-exchanged glass. The base lithium silicate composition 30Li2O–70SiO2 was studied as it underwent ion exchange, Li+ ↔ K+, ... -
Microwave-accelerated synthesis of benzyl 3,5-dimethyl-pyrrole-2-carboxylate
Benzyl 3,5-dimethyl-pyrrole-2-carboxylate, a very useful pyrrole in porphyrin and dipyrromethene synthesis, can be synthesized via the Knorr-type reaction, but in low yield. Alternative routes to benzyl 3,5-dimethyl-pyrr ... -
Microwave-assisted reduction of F-BODIPYs and dipyrrins to generate dipyrromethanes
The reduction of BODIPYs and dipyrrins to dipyrromethanes, via a reaction involving ethylene glycol and sodium methoxide, is reported. When benzyl alcohol is used in place of ethylene glycol, the addition of 2,4-dinitrop ... -
Nanoindentation Study of the Surface of Ion-Exchanged Lithium Silicate Glass
Variations in mechanical properties (stiffness and hardness) were measured as a function of case depth in ion-exchange glasses using nanoindentation. A simple silicate composition, 30Li2O–70Si2O, was exchanged (Li+ ↔ K+) ... -
The nature of ammonium ion disorder in ammonium tetrafluoroaluminate, NH4AlF4.
To clarify previous conflicting reports concerning the existence of an order-disorder phase transition in NH4AlF4 at T ?150 K, the heat capacity of this compd. was measured from T = 15 to 305 K, by adiabatic calorimetry. ... -
-
Phase transitions in M(ClO4)2.6H2O (M = magnesium, zinc). Investigations by adiabatic calorimetry and infrared spectroscopy.
IR spectra of Mg(ClO4)2.6H2O at 10 K indicate a complex structure contg. at least 16 distinct types of H2O protons. At 107.9 K this structure transforms sharply to a much simpler disordered form (?Strans = 7.754 J K-1 ...
