A molecular boron cluster-based chromophore with dual emission

2020 ◽  
Vol 49 (45) ◽  
pp. 16245-16251 ◽  
Author(s):  
Kierstyn P. Anderson ◽  
Mary A. Waddington ◽  
Gary J. Balaich ◽  
Julia M. Stauber ◽  
Nicholas A. Bernier ◽  
...  
Keyword(s):  
Electrophilic Substitution ◽  
Crystalline Solid ◽  
Dual Emission ◽  
Boron Cluster ◽  
Monosubstituted Derivative

Bromination of the luminescent borane, anti-B18H22, via electrophilic substitution using AlCl3 and Br2, yields the monosubstituted derivative 4-Br-anti-B18H21 as an air-stable crystalline solid.

scholarly journals A Molecular Boron Cluster-Based Chromophore with Dual Emission

2020 ◽  
Author(s):  
Kierstyn P. Anderson ◽  
Mary A. Waddington ◽  
Gary J. Balaich ◽  
Julia M. Stauber ◽  
Justin R. Caram ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Electrophilic Substitution ◽  
Uv Light ◽  
Parent Compound ◽  
Crystalline Solid ◽  
Oxygen Probe ◽  
Dual Emission ◽  
Fluorescent Signal ◽  
Boron Cluster ◽  
Monosubstituted Derivative

Bromination of the luminescent borane, anti-B18H22, via electrophilic substitution using AlCl3 and Br2 yields the monosubstituted derivative 4-Br-anti-B18H21 as an air-stable crystalline solid. In contrast to the unsubstituted parent compound, 4-Br-anti-B18H21 product possesses dual emission upon excitation with UV light and exhibits fluorescence at 410 nm and phosphorescence at 503 nm, with Фtotal = 0.07 in oxygen-free cyclohexane. Increased oxygen content in cyclohexane solution quenches the phosphorescence signal. The fluorescent signal intensity remains unaffected by oxygen, suggesting that this molecule could be used as a ratiometric oxygen probe.

scholarly journals A Molecular Boron Cluster-Based Chromophore with Dual Emission

2020 ◽  
Author(s):  
Kierstyn P. Anderson ◽  
Mary A. Waddington ◽  
Gary J. Balaich ◽  
Julia M. Stauber ◽  
Justin R. Caram ◽  
...  
Keyword(s):  
Signal Intensity ◽  
Electrophilic Substitution ◽  
Uv Light ◽  
Parent Compound ◽  
Crystalline Solid ◽  
Oxygen Probe ◽  
Dual Emission ◽  
Fluorescent Signal ◽  
Boron Cluster ◽  
Monosubstituted Derivative

Bromination of the luminescent borane, anti-B18H22, via electrophilic substitution using AlCl3 and Br2 yields the monosubstituted derivative 4-Br-anti-B18H21 as an air-stable crystalline solid. In contrast to the unsubstituted parent compound, 4-Br-anti-B18H21 product possesses dual emission upon excitation with UV light and exhibits fluorescence at 410 nm and phosphorescence at 503 nm, with Фtotal = 0.07 in oxygen-free cyclohexane. Increased oxygen content in cyclohexane solution quenches the phosphorescence signal. The fluorescent signal intensity remains unaffected by oxygen, suggesting that this molecule could be used as a ratiometric oxygen probe.

A Novel Heterooctametallic Metallacarborane Tetramer

1999 ◽  
Vol 64 (5) ◽  
pp. 819-828 ◽  
Author(s):  
Keith G. Parker ◽  
J. Monte Russell ◽  
Michal Sabat ◽  
Russell N. Grimes
Keyword(s):  
Molecular Geometry ◽  
Crystalline Solid ◽  
Covalent Bonds ◽  
Cluster Chemistry ◽  
X Ray ◽  
Boron Cluster ◽  
Double Decker ◽  
Ruthenium Atom ◽  
Yellow Orange

The synthesis and X-ray crystal structure determination of [(2,3-Et2C2B4H4)Co(2,3-Et2C2B3H3-5-Bu)Ru]4 (3) are reported. Complex 3 was obtained serendipitously in low yield from a reaction of [(η4-C8H12)Ru(MeCN)4][PF6]2 with the (Et2C2B4H4)Co(Et2C2B3H3Bu)2- anion in THF solution at room temperature. The molecular geometry of 3, isolated as a yellow-orange crystalline solid, is without precedent in boron cluster chemistry and consists of an array of four (Et2C2B4H4)Co(Et2C2B3H3Bu)Ru units linked via intercluster Ru-B covalent bonds. Each cluster moiety contains a double-decker (C2B4)Co(C2B3) sandwich with an exo-polyhedral ruthenium atom occupying a "wedging" position in which it is bound to the C2B3 and the C2B4 ligands as well as to a neighboring sandwich unit.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Electron-Channelling Patterns: Principles and Techniques

1976 ◽  
Vol 34 ◽  
pp. 400-401
Author(s):  
David C. Joy
Keyword(s):  
Crystal Structure ◽  
Electron Flux ◽  
Lattice Structure ◽  
Incident Beam ◽  
Bloch Wave ◽  
Crystalline Solid ◽  
Angle Of Incidence ◽  
Electron Channelling ◽  
Regular Arrangement ◽  
Backscattered Signals

In a crystalline solid the regular arrangement of the lattice structure influences the interaction of the incident beam with the specimen, leading to changes in both the transmitted and backscattered signals when the angle of incidence of the beam to the specimen is changed. For the simplest case the electron flux inside the specimen can be visualized as the sum of two, standing wave distributions of electrons (Fig. 1). Bloch wave 1 is concentrated mainly between the atom rows and so only interacts weakly with them. It is therefore transmitted well and backscattered weakly. Bloch wave 2 is concentrated on the line of atom centers and is therefore transmitted poorly and backscattered strongly. The ratio of the excitation of wave 1 to wave 2 varies with the angle between the incident beam and the crystal structure.

The Chemistry of Triazine Isomers: Structures, Reactions, Synthesis and Applications

2020 ◽  
Vol 20 ◽  
Author(s):  
Neelottama Kushwaha ◽  
C S Sharma
Keyword(s):  
Basic Property ◽  
Electrophilic Substitution ◽  
Antimicrobial Agents ◽  
Resonance Energy ◽  
Heterocyclic Ring ◽  
Ring System ◽  
Agricultural Fields ◽  
Substitution Reactions ◽  
Anti Cancer ◽  
Benzene Structure

: Triazine is the six-membered heterocyclic ring containing three nitrogen which replaces carbon-hydrogen unit in the benzene ring. Based on nitrogen position present in the ring system, it is categorized in three isomeric forms i.e.1, 2, 3-triazine (vicinal triazine), 1, 2, 4-triazine (asymmetrical triazine or isotriazine) and 1, 3, 5-triazine (symmetrical or s-triazine or cyanidine). Triazines have weakly basic property. Its isomers have much weaker resonance energy than benzene structure, so nucleophilic substitution reactions are more preferred than electrophilic substitution reactions. Triazine isomers and their derivatives are known to play important roles possessing various activities in medicinal and agricultural fields such as anti-cancer, antiviral, fungicidal, insecticidal, bactericidal, herbicidal, antimalarial and antimicrobial agents.

Oxidation of polysubstituted pyridinium salts

1982 ◽  
Vol 47 (5) ◽  
pp. 1494-1502 ◽  
Author(s):  
Petr Nesvadba ◽  
Josef Kuthan
Keyword(s):  
Alkaline Medium ◽  
Electrophilic Substitution ◽  
Pyridine Ring ◽  
Potassium Ferricyanide ◽  
Pyridinium Salts ◽  
Complex Reaction

Oxidation of 1-substituted 2,4,6-triphenylpyridinium salts Ia-Ij with potassium ferricyanide in an alkaline medium was accompanied by contraction of the pyridine ring and formation of 1,2,3,5-tetrasubstituted pyrroles II. The derivative IIf underwent facile electrophilic substitution in the position 4. Contrary to compounds Ia-Ij, the 1-substituted-2,6-diphenylpyridinium salts IIIa,b were oxidized to give a complex reaction mixture containing 4-pyridones IVa,b.

Reversible two-channel mechanochromic luminescence for a pyridinium-based white-light emitter with room-temperature fluorescence–phosphorescence dual emission

2019 ◽  
Vol 21 (27) ◽  
pp. 14728-14733 ◽  
Author(s):  
Xiao Ma ◽  
Jipeng Li ◽  
Chensheng Lin ◽  
Guoliang Chai ◽  
Yangbin Xie ◽  
...  
Keyword(s):  
White Light ◽  
Room Temperature ◽  
Mechanical Grinding ◽  
Dual Emission ◽  
Light Emitter ◽  
Mechanical Pressing ◽  
Mechanochromic Luminescence ◽  
White Light Emitter

For a pyridinium-based emitter with fluorescence–phosphorescence dual emission, mechanical grinding induces phosphorescence disappearance and mechanical pressing induces extraordinary phosphorescence enhancement.

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