Solid-state emission enhancement in vaulted trans-bis(salicylaldiminato)platinum(ii) crystals with halogen functionality

2014 ◽  
Vol 43 (26) ◽  
pp. 10074-10085 ◽  
Author(s):  
Naruyoshi Komiya ◽  
Minoru Okada ◽  
Kanako Fukumoto ◽  
Shotaro Iwata ◽  
Takeshi Naota
Keyword(s):  
Solid State ◽  
Heat Resistance ◽  
Structural Dependence ◽  
Emission Enhancement ◽  
Lower Heat ◽  
Intense Emission ◽  
Complex Crystals

Chloro-substitution significantly increases the lower heat resistance of short-vaulted, non-substituted trans-bis(salicylaldiminato)Pt(ii) complex crystals, and maintains the intense emission of long-vaulted analogues, which leads to intense solid-state emission with low structural dependence.

scholarly journals Switching-On Fluorescence by Copper (II) and Basic Anions: A Case Study with a Pyrene-Functionalized Squaramide

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1301
Author(s):  
Giacomo Picci ◽  
Jessica Milia ◽  
Maria Carla Aragoni ◽  
Massimiliano Arca ◽  
Simon J. Coles ◽  
...  
Keyword(s):  
Solid State ◽  
Copper Complex ◽  
Receptor Complex ◽  
Emission Properties ◽  
Naked Eye ◽  
Intense Emission ◽  
Uv Lamp

The new symmetric acyclic N,N’-bis(1-pyrenyl) squaramide (H2L) functionalized with the pyrene moiety as a fluorogenic fragment has been designed and its ability to selectively detect specific anions and metals investigated. H2L selectively binds Cl− both in solution (DMSO 0.5% H2O and MeCN) and in the solid state, and allows to selectively detect Cu2+ in MeCN with the formation of a 2:1 metal-receptor complex, with a green intense emission appreciable by naked eye under the UV lamp. The H2L copper complex preserves its emission properties in the presence of Cl−. The addition of basic anions (OH−, CN−, and F−) up to 10 equivalents caused the deprotonation of the squaramide NHs and a dramatic change of the emission properties of the H2L copper complex.

Benzothiazole–pyrimidine-based BODIPY analogues: promising luminophores with fluorescence sensing and imaging ability and asymmetrization-induced solid-state emission

2016 ◽  
Vol 45 (43) ◽  
pp. 17274-17280 ◽  
Author(s):  
Xiaoqing Wang ◽  
Qingsong Liu ◽  
Fen Qi ◽  
Lin Li ◽  
Hai-Dong Yu ◽  
...  
Keyword(s):  
Solid State ◽  
Fluorescence Sensing ◽  
Intense Emission ◽  
Boron Difluoride

A series of boron difluoride dyes were demonstrated to possess intense emission both in solution and solid-state. Their fluorogenic sensing and imaging abilities were also investigated.

scholarly journals Nitrile-Substituted 2-(Oxazolinyl)-Phenols: Minimalistic Excited-State Intramolecular Proton Transfer (ESIPT)-Based Fluorophores

2020 ◽  
Author(s):  
Dominik Göbel ◽  
Daniel Duvinage ◽  
Tim Stauch ◽  
Boris Nachtsheim
Keyword(s):  
Excited State ◽  
Solid State ◽  
Proton Transfer ◽  
Density Functional ◽  
Intramolecular Proton Transfer ◽  
Crystal Structure Analysis ◽  
Quantum Yields ◽  
Functional Theory ◽  
Emission Properties ◽  
Emission Enhancement

Herein, we present minimalistic single-benzene, excited-state intramolecular proton transfer (ESIPT) based fluorophores as powerful solid state emitters. The very simple synthesis gave access to all four regioisomers of nitrile-substituted 2(oxazolinyl)phenols (MW = 216.1). In respect of their emission properties they can be divided into aggregation-induced emission enhancement (AIEE) luminophores (1-CN and 2-CN), dual state emission (DSE) emitters (3-CN) and aggregation-caused quenching (ACQ) fluorophores (4‐CN). Remarkably, with compound 1-CN we discovered a minimalistic ESIPT based fluorophore with extremely high quantum yield in the solid state ΦF = 87.3% at λem = 491 nm. Furthermore, quantum yields in solution were determined up to ΦF = 63.0%, combined with Stokes shifts up till 11.300 cm–1. Temperature dependent emission mapping, crystal structure analysis and time-dependent density functional theory (TDDFT) calculations gave deep insight into the origin of the emission properties.<br>

Synthesis and Spectroscopic Characteristics of Ligands Based on Quinolin-8-Ol as Useful Precursors for Alq3 Type Complexes

2021 ◽  
Vol 903 ◽  
pp. 168-173
Author(s):  
Elmārs Zariņš ◽  
Deins Alksnis ◽  
Patricija Paulsone ◽  
Karlis Balodis ◽  
Aivars Vembris ◽  
...  
Keyword(s):  
Solid State ◽  
Light Emission ◽  
Emission Property ◽  
Blue Luminescence ◽  
Reaction Conditions ◽  
Aggregation Induced Emission ◽  
Chemical Structures ◽  
Emission Enhancement ◽  
Spectroscopic Characteristics ◽  
Reliable Methods

In order to develop reliable methods for the synthesis of various 5-substituted-8-oxyquinoline derivatives for the preparation of Alq3-type complexes, we have improved the reaction conditions on some syntheses described in the literature, successfully synthesized new ligands based on quinolin-8-ol and characterized their chemical structures by NMR. Some of the synthesized quinolin-8-ol derivatives containing incorporated bulky triphenyl or tert-butyl groups showed blue luminescence in the solid state due to the possible aggregation induced emission enhancement (AIEE) with a maximum wavelength around 510 nm. More detailed light-emission property investigation of the mentioned bulky group containing compounds is currently underway.

Changes in Heat Resistance Resulting from pH and Nutritional Shifts of Acid-Adapted and Non–Acid-Adapted Listeria monocytogenes Scott A†

2004 ◽  
Vol 67 (2) ◽  
pp. 316-321 ◽  
Author(s):  
DARRELL O. BAYLES
Keyword(s):  
Listeria Monocytogenes ◽  
Heat Resistance ◽  
Frequency Distribution ◽  
Culture Supernatant ◽  
Physiological State ◽  
Distribution Data ◽  
Treatment Conditions ◽  
Lower Heat ◽  
Full Factorial ◽  
Cell Free Culture Supernatant

Stationary-phase Listeria monocytogenes cells that were either pH dependent acid adapted or not acid adapted were heat challenged at 60°C in a two-level full factorial design for three variables. The three variables and the levels consisted of tryptic soy broth (TSB) and sterile cell-free culture supernatant (sterile TSB), the presence and absence of 1% added glucose, and pH 4.8 and pH 7. Non–acid-adapted cells were most heat resistant when challenged in TSB (mean decimal reduction times at 60°C: D60 = 1.16 min). In the absence of added glucose, non–acid-adapted cells had similar D60-values for inactivations at pH 4.8 and pH 7; however, the presence of glucose caused non–acid-adapted cells challenged at pH 4.8 to be more heat sensitive (D60 = 0.65 min) than those inactivated at pH 7 (D60 = 1.03 min), indicating an interaction between glucose and pH. Overall, the significantly decreased heat resistance of the acid-adapted cells was due to the presence of glucose (D60 = 0.78 min without glucose, D60 = 0.59 min with glucose). Acid-adapted cells heat challenged in TSB had similar D60-values for inactivations at pH 4.8 and pH 7; however, acid-adapted cells in sterile TSB challenged at pH 4.8 (D60 = 0.52 min) had significantly lower heat resistance than did cells challenged at pH 7 (D60 = 0.76 min), indicating an interaction between the medium and pH. The L. monocytogenes survivor data were modeled to extract information on the frequency distribution of heat resistance within heat-challenged populations, and the frequency distribution characteristics of mean, mode, and variance were compared among treatment conditions. Significant differences in the frequency distribution data were compared with the D60-values. These data indicated that the presence and level of cross-protection is highly dependent on the physiological state of the cells and nutrient availability at the time of heat challenge. Such conditions should be considered to ensure that stressed pathogens in foods are destroyed or inactivated.

scholarly journals Daqu Fermentation Selects for Heat-ResistantEnterobacteriaceaeand Bacilli

2018 ◽  
Vol 84 (21) ◽  
Author(s):  
Zhiying Wang ◽  
Pan Li ◽  
Lixin Luo ◽  
David J. Simpson ◽  
Michael G. Gänzle
Keyword(s):  
Solid State ◽  
Heat Resistance ◽  
Pathogenic Bacteria ◽  
Starter Culture ◽  
Genomic Islands ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Content Type ◽  
Genetic Elements ◽  
Heat Resistant

ABSTRACTDaqu is a spontaneous solid-state cereal fermentation used as saccharification and starter culture in Chinese vinegar and liquor production. The evolution of microbiota in this spontaneous fermentation is controlled by the temperature profile, which reaches temperatures from 50 to 65°C for several days. Despite these high temperatures, mesophilicEnterobacteriaceae(includingCronobacter) and bacilli are present throughout Daqu fermentation. This study aimed to determine whether Daqu spontaneous solid-state fermentation selects for heat-resistant variants of these organisms. Heat resistance inEnterobacteriaceaeis mediated by the locus of heat resistance (LHR). One LHR-positive strain ofKosakonia cowaniiwas identified in Daqu, and it exhibited higher heat resistance than the LHR-negativeK. cowaniiisolated from malted oats. Heat resistance inBacillusendospores is mediated by thespoVA2moboperon. Out of 10 Daqu isolates of the speciesBacillus licheniformis,Brevibacillus parabrevis,Bacillus subtilis,Bacillus amyloliquefaciens, andBacillus velezensis, 5 did not containspoVA2mob, 3 contained one copy, and 2 contained two copies. The presence and copy number of thespoVA2moboperon increased the resistance of spores to treatment with 110°C. To confirm the selection of LHR- andspoVA2mob-positive strains during Daqu fermentation, the copy numbers of these genetic elements in Daqu samples were quantified by quantitative PCR (qPCR). The abundance of LHR and thespoVA2moboperon in community DNA relative to that of total bacterial 16S rRNA genes increased 3-fold and 5-fold, respectively, during processing. In conclusion, culture-dependent and culture-independent analyses suggest that Daqu fermentation selects for heat-resistantEnterobacteriaceaeand bacilli.IMPORTANCEDaqu fermentations select for mobile genetic elements conferring heat resistance inEnterobacteriaceaeand bacilli. The locus of heat resistance (LHR), a genomic island conferring heat resistance inEnterobacteriaceae, and thespoVA2moboperon, conferring heat resistance on bacterial endospores, were enriched 3- to 5-fold during Daqu fermentation and maturation. It is therefore remarkable that the LHR and thespoVA2moboperon are accumulated in the same food fermentation. The presence of heat-resistantKosakoniaspp. andBacillusspp. in Daqu is not of concern for food safety; however, both genomic islands are mobile and transferable to pathogenic bacteria or toxin-producing bacteria by horizontal gene transfer. The identification of the LHR and thespoVA2moboperon as indicators of fitness ofEnterobacteriaceaeand bacilli in Daqu fermentation provides insights into environmental sources of heat-resistant organisms that may contaminate the food supply.

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