An Investigation into the Reactivity of Organometallic Noble Gas Complexes:  A Time-Resolved Infrared Study in Supercritical Noble Gas and Alkane Solution at Room Temperature

2000 ◽  
Vol 104 (18) ◽  
pp. 4300-4307 ◽  
Author(s):  
David C. Grills ◽  
Xue Z. Sun ◽  
Gavin I. Childs ◽  
Michael W. George
Keyword(s):  
Room Temperature ◽  
Noble Gas ◽  
Infrared Study ◽  
Time Resolved

scholarly journals Time-Resolved Infrared Spectroscopy in Supercritical Fluids

1999 ◽  
Vol 19 (1-4) ◽  
pp. 133-139 ◽  
Author(s):  
Michael W. George ◽  
Martyn Poliakoff ◽  
Xue-Zhong Sun ◽  
David C. Grills
Keyword(s):  
Infrared Spectroscopy ◽  
Supercritical Fluids ◽  
Room Temperature ◽  
Noble Gas ◽  
Fast Time ◽  
Metal Carbonyls ◽  
Time Resolved ◽  
Organometallic Reactions ◽  
Time Resolved Infrared Spectroscopy ◽  
First Time

We have used fast Time-resolved Infrared Spectroscopy (TRIR) to probe organometallic reactions in supercritical fluids on the nanosecond time-scale. This has allowed us to identify, for the first time in solution at room temperature, organometallic noble gas complexes which are formed following irradiation of metal carbonyls in supercritical noble gas solution. We have found that these complexes are surprisingly stable and have comparable reactivity to organometallic alkane complexes. We have also studied the coordination of CO2 to metal centres in supercritical CO2 (scCO2) and provide the first evidence for the formation and reactivity of ɳ1-O bound metal CO2 complexes in solution at or above room temperature.

Photochemistry of 2-(Methoxycarbonyl)phenyl Azide in Solution at Room Temperature: A Time-resolved Infrared Study

1996 ◽  
Vol 25 (12) ◽  
pp. 1089-1090 ◽  
Author(s):  
Xue-Zhong Sun ◽  
Ian G. Virrels ◽  
Michael W. George ◽  
Hideo Tomioka
Keyword(s):  
Room Temperature ◽  
Phenyl Azide ◽  
Infrared Study ◽  
Time Resolved

Recent advances in organometallic alkane and noble gas complexes

2009 ◽  
Vol 81 (9) ◽  
pp. 1667-1675 ◽  
Author(s):  
James A. Calladine ◽  
Khuong Q. Vuong ◽  
Xue Z. Sun ◽  
Michael W. George
Keyword(s):  
Nmr Spectroscopy ◽  
Room Temperature ◽  
Noble Gas ◽  
Metal Carbonyl ◽  
Fast Time ◽  
Time Resolved ◽  
New Approach ◽  
Metal Centers ◽  
Wide Range ◽  
Metal Ligand

Fast time-resolved infrared (TRIR) spectroscopy has been useful for studying the reactions of a wide range of organometallic alkane and noble gas complexes at ambient temperature following irradiation of metal carbonyl precursor complexes. The reactivity of organometallic alkane and xenon complexes decreases both across and down groups V, VI, and VII, and for a given metal/ligand combination the alkane and xenon complexes have similar reactivities. Systematic studies of reactivity have produced long-lived Re complexes which have allowed such complexes to be characterized using NMR spectroscopy. A new approach using liquid propane at low temperature as a solvent to monitor the interaction of such weakly coordinating ligands with transition-metal centers is outlined. TRIR studies monitoring the coordination and activation of methane and ethane in supercritical methane and liquid ethane solvents at room temperature are also reviewed.

Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

1987 ◽  
Vol 52 (5) ◽  
pp. 1356-1361
Author(s):  
S. Abdel Rahman ◽  
M. Elsafty ◽  
A. Hattaba
Keyword(s):  
Circular Dichroism ◽  
Solid State ◽  
Ir Spectra ◽  
Chain Length ◽  
Room Temperature ◽  
Infrared Study ◽  
Feature Characteristic ◽  
C 50 ◽  
The Stability ◽  
Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

Photophysical properties of N719 and Z907 dyes, benchmark sensitizers for dye-sensitized solar cells, at room and low temperature

2021 ◽  
Vol 23 (10) ◽  
pp. 6182-6189
Author(s):  
Dariusz M. Niedzwiedzki
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
Optical Spectroscopy ◽  
Room Temperature ◽  
Photophysical Properties ◽  
Dye Sensitized Solar Cells ◽  
Time Resolved ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Photophysical properties of N719 and Z907, benchmark Ru-dyes used as sensitizers in dye-sensitized solar cells, were studied by static and time-resolved optical spectroscopy at room temperature and 160 K.

Lead inclusions in aluminium

1989 ◽  
Vol 157 ◽  
Author(s):  
E. Johnson ◽  
L. Gråbaek ◽  
J. Bohr ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Room Temperature ◽  
Noble Gas ◽  
Melting Transition ◽  
X Ray Diffraction ◽  
Free Surfaces ◽  
The Matrix ◽  
Mean Size ◽  
The Mean ◽  
Spontaneous Phase

ABSTRACTIon implantation at room temperature of lead into aluminium leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurised (∼ 1–5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa.Recently we have observed the intriguing result that the lead inclusions in aluminium exhibit both superheating and supercooling [1]. In this paper we review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminium matrix were studied by X-ray diffraction. The (111) Bragg peak originating from the lead crystals was followed during several temperature cycles, from room temperature to 678 K. The melting temperature for bulk lead is 601 K. In the first heating cycle we found a superheating of the lead precipitates of 67 K before melting occurred. During subsequent cooling a supercooling of 21 K below the solidification point of bulk lead was observed. In the subsequent heating cycles this hysteresis at the melting transition was reproducible. The full width of the hysteresis loop slowly decreased to 62 K, while the mean size of the inclusions gradually increased from 14.5 nm to 27 nm. The phenomena of superheating and supercooling are thus most pronounced for the small crystallites. The persistence of the hysteresis loop over successive heating cycles demonstrate that its cause is intrinsic in nature, and it is believed that the superheating originates from the lack of free surfaces of the lead inclusions.

Luminescence and Time-Resolved Infrared Study of Dyads Containing (Diimine)Ru(4,4′-diethylamido-2,2′-bipyridine)2and (Diimine)Ru(CN)4Moieties: Solvent-Induced Reversal of the Direction of Photoinduced Energy-Transfer

2009 ◽  
Vol 48 (18) ◽  
pp. 8759-8770 ◽  
Author(s):  
Timothy L. Easun ◽  
Wassim Z. Alsindi ◽  
Nina Deppermann ◽  
Michael Towrie ◽  
Kate L. Ronayne ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Infrared Study ◽  
Time Resolved

Infrared study of methanol adsorption on Aerosil. I. Chemisorption at room temperature

1967 ◽  
Vol 71 (9) ◽  
pp. 2938-2945 ◽  
Author(s):  
Enzo Borello ◽  
Adriano Zecchina ◽  
Claudio Morterra
Keyword(s):  
Room Temperature ◽  
Infrared Study ◽  
Methanol Adsorption
Sign in / Sign up

Export Citation Format

Share Document