Synthesis and mesogenic properties of β-tetrabrominated tetraalkyloxyporphyrins

2008 ◽  
Vol 12 (01) ◽  
pp. 54-64 ◽  
Author(s):  
Puttaiah Bhyrappa ◽  
Chellaiah Arunkumar ◽  
Babu Varghese ◽  
Doddamane S. Shankar Rao ◽  
Subbarao K. Prasad
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Scanning Calorimetry ◽  
Point Temperature ◽  
New Class ◽  
Clearing Point

A new class of 2,3,7,8-tetrabromo-5,10,15,20-tetrakis(4'-n-1-alkyloxyphenyl)porphyrins, H 2 T (4'- OC n P ) PBr 4 (n = 4,6,8,10,12,14,16 and 18) and their Cu(II) complexes have been synthesized regioselectively and their mesophase properties explored. The mesogenic properties of the porphyrins were examined by differential scanning calorimetry and optical microscopy. An increase in alkyl chain length of the mesogens, showed an increase in melting point temperature and lowering of their clearing point temperatures with the narrower mesophases. This has been ascribed to the decreased π-π interactions as evidenced from the crystal structure of H 2 T (4'- OC 6 P ) PBr 4· THF derivative. MT (4'- OC n P ) PBr 4 derivatives showed rectangular mesophases in contrast to discotic lamellar mesophases reported for the planar MT (4'- OC n P ) P mesogens.

Characterization, liquid crystallinity and spin-coated films of some metalated 1,4,8,11,15,18,22,25-octaalkyl tetrabenzo [b,g,l,q][5,10,15]triazaporphyrin derivatives

2011 ◽  
Vol 15 (09n10) ◽  
pp. 890-897 ◽  
Author(s):  
Andrew N. Cammidge ◽  
Isabelle Chambrier ◽  
Michael J. Cook ◽  
Ernie H.G. Langner ◽  
Muhibur Rahman ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Bulk Material ◽  
Polarized Light ◽  
Scanning Calorimetry ◽  
Liquid Crystallinity ◽  
Derivatives Of ◽  
Deposited Films

The preparation and characterization of a number of metalated derivatives of 1,4,8,11,15,18,22,25-octahexyl and 1,4,8,11,15,18,22,25-octadecyl tetrabenzotriazaporphyrins (TBTAPs) are reported. The mesophase behavior of the compounds has been characterized by differential scanning calorimetry (DSC) and by polarized light optical microscopy. Mesophase behavior is compared with data for the corresponding phthalocyanine derivatives reported earlier. The temperature range of the mesophase(s) exhibited by the title compounds is generally broader than those of their phthalocyanine analogs. UV-vis data for examples of the TBTAP compounds as spin-coated films reveal differences in the type of molecular packing in the as-deposited films that is largely dependent upon the length of the alkyl chain substituents. On heating, the films undergo molecular reorganizations at temperatures corresponding to the mesophase transitions of bulk material observed by DSC.

Synthesis, Electrochemical, and Thermal Properties of [3]Ferrocenophane-Containing Chalcone Derivatives

2015 ◽  
Vol 68 (7) ◽  
pp. 1035 ◽  
Author(s):  
Haiying Zhao ◽  
Xueyou Zhu ◽  
Dong Wang ◽  
Shufeng Chen ◽  
Zhanxi Bian
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Phase Transitions ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Freezing Process ◽  
Naphthalene Ring ◽  
Scanning Calorimetry ◽  
Chalcone Derivatives ◽  
Heating And Cooling

[3]Ferrocenophane-containing chalcone derivatives with benzene ring (3a–3d) or naphthalene ring (3e–3f) were synthesized and characterized. The potentials for [3]ferrocenophane-containing chalcones cathodically shifted ~70–80 mV compared with those of ferrocene-containing chalcones, indicating easier oxidation by loss of an electron for the former. The thermal behaviours of the prepared compounds were studied by differential scanning calorimetry and polarizing optical microscopy. Compound 3f with terminal alkyl chain of 14 carbon atoms displayed mesophases, whereas other compounds were non-mesomorphic and showed either crystal polymorphic phase transitions or simple melting and freezing process in the heating and cooling cycles.

Screening of Carbamazepine-Ibuprofen Co-Crystal Formation Using Non-Stoichiometric and Stoichiometric Methods

2015 ◽  
Vol 1113 ◽  
pp. 417-421 ◽  
Author(s):  
Syarifah Abd Rahim ◽  
Nurul Aini Rosli ◽  
Siti Salasiah Mohd Khalid
Keyword(s):  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Formic Acid ◽  
Optical Microscopy ◽  
Crystal Formation ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Screening Process ◽  
Dry Grinding ◽  
Screening Study

The paper presents the co-crystal screening study of carbamazepine (CBZ) and ibuprofen (IBU) as a co-crystal former (CCF) using non-stoichiometric (solid addition of CBZ to saturated solution of co-crystal former (CCF) and stoichiometric (1:1 mol of CBZ and CCF) methods. In the non-stoichiometric method, CBZ-IBU co-crystal was prepared in various solvents and left to equilibrate in three conditions; stagnant, manually agitated and shaking in 72 hours whereas in the stoichiometric method, evaporation, solvent drop grinding and dry grinding were used. The crystals produced from the screening process were characterized using differential scanning calorimetry (DSC) and optical microscopy. The co-crystal of CBZ-IBU was found to have successfully formed via the non-stoichiometric method in formic acid. DSC analysis revealed that the remaining crystals produced were either CBZ or IBU as indicated by their respective melting point.

scholarly journals Effect of the dispersion of the chromophore on the optical performances of polarizers from polyethylene and 5”-thio- (3-butyl)nonyl-2,2’:5’,2”-terthiophene

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrea Pucci ◽  
Letizia Moretto ◽  
Giacomo Ruggeri ◽  
Francesco Ciardelli
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Drawing Ratio ◽  
Scanning Calorimetry ◽  
Affine Deformation ◽  
Ultra High Molecular Weight ◽  
Scanning Electron

AbstractA new polyethylene-compatible terthiophene chromophore, 5”-thio-(3- butyl)nonyl-2,2’:5’,2”-terthiophene, with melting point lower than 0°C was prepared and used for linear polarizers based on ultra-high-molecular-weight polyethylene (UHMWPE). Differential scanning calorimetry and scanning electron microscopy indicate that the new chromophore is dispersed uniformly in films of UHMWPE obtained by casting from solution. The films show excellent dichroic properties (dichroic ratio 30) at rather low drawing ratio (≈ 20) . Moreover, qualitative agreement is observed with the Ward pseudo-affine deformation scheme.

Effects of In and Sb addition on the thermal and wetting behavior of Sn-3.5Ag solder

2018 ◽  
Vol 30 (4) ◽  
pp. 233-240 ◽  
Author(s):  
Md Hasnine
Keyword(s):  
Differential Scanning Calorimetry ◽  
Melting Point ◽  
Thermal Behavior ◽  
Surface Finish ◽  
Design Methodology ◽  
Solder Alloys ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Cu Substrate ◽  
Free Solder

Purpose This paper aims to investigate the effect of In and Sb additions on the thermal behavior and wettability of Sn-3.5Ag-xIn-ySb (x = 0, 1.0 and 1.5 Wt.%, y = 0, 1.0, 1.4 and 2.1 Wt.%) solder alloys. Design/methodology/approach The thermal behavior of the Pb-free solder alloys was studied using differential scanning calorimetry. Wetting balance experiments were performed in accordance with the IPC standard, IPC-TM-650 and at a temperature of 260°C. Also, a solder spread test was performed on a Cu surface finish using the JIS-Z-3197 solderability standard. Findings It is shown that among the selected Sn-3.5Ag-xIn-ySb (x = 0, 1.0 and 1.5 Wt.%, y = 0, 1.0, 1.4 and 2.1 Wt.%) alloys, Sn-3.5Ag-1.5In-1Sb showed the lowest melting point and the lowest undercooling temperature. The best wettability was achieved when the In and Sb contents were approximately 1.5 and 1.0 Wt.%, respectively. The effect of the combined addition of In and Sb on solder spreadability on a Cu substrate was also demonstrated. Originality/value It was found that adding approximately 1.5 and 1.0 Wt.% of In and Sb, respectively, in Sn-3.5Ag solder provided the best wetting performance and improved the solder spreadability.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

Molecular Dynamics and Kinetics of Isothermal Cold Crystallization in the Chiral Smectogenic 3F7HPhH6 Glassformer

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1487
Author(s):  
Aleksandra Deptuch ◽  
Małgorzata Jasiurkowska-Delaporte ◽  
Ewa Juszyńska-Gałązka ◽  
Anna Drzewicz ◽  
Wojciech Zając ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Optical Microscopy ◽  
Dielectric Spectroscopy ◽  
Cold Crystallization ◽  
Scanning Calorimetry ◽  
Broadband Dielectric Spectroscopy ◽  
Smectic C ◽  
Dimension Analysis ◽  
Fractal Dimension Analysis ◽  
Kinetics Of

An investigation of the glass transition of the antiferroelectric smectic C*A phase and cold crystallization of (S)-4’-(1-methylheptylcarbonyl)biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluoro- butoxy)heptyl-1-oxy]benzoate (denoted as 3F7HPhH6) by differential scanning calorimetry, polarizing optical microscopy and broadband dielectric spectroscopy is presented. The fragility index mf = 72, classifying 3F7HPhH6 as a glassformer with intermediate fragility, was obtained from the temperature dependence of the α-process relaxation time, measured upon cooling. Duplication of the α-process was observed exclusively upon heating, before the onset of cold crystallization, and is connected with the pre-transitional effect. The presence of two crystal phases likely influences the kinetics of cold crystallization; the idea stems from a comparison with previous results for the 3F7HPhF6 and 3F7HPhH7 compounds. Additionally, the presence of the smectic C*α; sub-phase in a narrow temperature range was proved based on the differential scanning calorimetry and broadband dielectric spectroscopy results, as well as the fractal dimension analysis of the textures obtained by polarizing optical microscopy.

scholarly journals Phase Polymorphism of [Co(DMSO)6](BF4)2 Studied by Differential Scanning Calorimetry

2006 ◽  
Vol 61 (3-4) ◽  
pp. 180-188 ◽  
Author(s):  
Anna Migdał-Mikuli ◽  
Łukasz Skoczylas ◽  
Elżbieta Szostak
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Transitions ◽  
Melting Point ◽  
Title Compound ◽  
Metastable Phases ◽  
Scanning Calorimetry ◽  
Phase Polymorphism ◽  
Solid Phases ◽  
High Degree ◽  
Dynamical Disorder

Five solid phases of [Co(DMSO)6](BF4)2 have been detected by differential scanning calorimetry (DSC). Phase transitions were detected between the following solid phases: stable KIb↔ stable KIa at T̅C4 = (328±2) K, metastable KIII ↔ undercooled phase K0 at T̅C3 = (383±4) K, metastable KII ↔ undercooled K0 at T̅C2 = (399±2) K and stable KIa ↔ stable K0 at T̅C1 = (404±1) K. The title compound melts at Tm = 440 K. From the entropy changes at the melting point and at phase transitions it can be concluded that the phases K0 and undercooled K0 are orientationally dynamically disordered crystals. The stable phases KIa, KIb are ordered solid phases. The metastable phases KII and KIII are probably solid phases with a high degree of orientational dynamical disorder

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