Influence of oxygen in lower homologues of Schiff-base compounds: a comparative study

Ajeetha, N.; Potukuchi, D. M.; Pisipati, V. G. K. M.

doi:10.1080/01411590500114716

Cited by 6 publications

(2 citation statements)

References 8 publications

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“…But the effect is less prominent in the case of middle homology (5O.5 and 5.O5) because both are exhibiting liquid crystalline nature at above room temperature level [13]. Furthermore, in lower homologous series like 1O.5, 1.O5, 2O.5, and 2.O5, there is no pronounced effect observed on melting/clearing temperature, but quenching of liquid crystallinity is observed in case of 1.O5 and 2.O5 [14]. The change in the position of the oxygen atom has a pronounced effect on higher homologous series compared to lower homologous one.…”

Section: Influence Of Oxygen Positionmentioning

confidence: 83%

Role of Oxygen on Phase Behaviour of Benzylidene Aniline – A Comparative Study

Ajeetha¹,

Ojha²

2009

Zeitschrift Für Naturforschung A

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Four structurally related Schiff's base compounds are synthesized and their mesogenic properties are characterized by using Thermal Microscopy (TM) and Differential Scanning Calorimetry (DSC). The position of oxygen is varied from either sides of the bridging site, oxygen introduced on both sides and the oxygen is removed from the bridging site for the values of n = 8 and m = 5. The influence of oxygen atom to the extent of increase in thermal range, depression in melting temperature, elevation of clearing temperature is observed for all four compounds, viz. N (p-n-Octyloxy benzylidene) p-n-Pentyl aniline (8O.5), N (p-n-Octyl benzylidene) p-n-Pentyloxy aniline (8.O5), N (p-n-Octyloxy benzylidene) p-n-Pentyloxy aniline (8O.O5), and N (p-n-Octyl benzylidene) p-nPentyl aniline (8.5). The shift in the position of oxygen from the aldehyde to the aniline side and the removal of oxygen has a greater effect as they become room temperature liquids, whereas the oxygen on the aldehyde side and the oxygen on both sides of the rigid core moiety effect only the clearing temperatures. The results obtained are discussed in the light of the earlier data available on Schiff's base nO.m compounds.

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Section: Influence Of Oxygen Positionmentioning

confidence: 83%

Role of Oxygen on Phase Behaviour of Benzylidene Aniline – A Comparative Study

Ajeetha¹,

Ojha²

2009

Zeitschrift Für Naturforschung A

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“…In the field of liquid crystal research, it is common to look at the new compounds through the design and synthesis [1][2][3][4]. The thermal measurements (polarizing microscope attached with hot stage and differential scanning calorimeter) play an important role in finding and characterizing the different phases and phase transitions in the liquid crystal compounds [5].…”

Section: Introductionmentioning

confidence: 99%

Accurate Method for the Determination of Phase Transitions in Liquid Crystals with Photoacoustic Technique

Lakshminarayana¹,

Gouthami²,

Pisipati³

et al. 2009

Molecular Crystals and Liquid Crystals

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A compact Photoacoustic spectrometer (PAS) was fabricated, for the determination of phase transitions in liquid crystals (LCs). Photoacoustic (PA) technique is a powerful tool for the determination of phase transitions in solids, liquids and gasses compared to other techniques like Raman spectroscopy, Newton scattering, NMR & ultrasound studies and DSC. PA signal information is used to investigate the variations in the optical and thermal properties of the materials during phase transitions. The advantage of PA technique is its simplicity in the sample preparation, and its accuracy in the phase transition studies. The instrumentation details and results of phase transition studies on p-pentyloxy benzoic acid (5OBA), N(4-n-hexadcyloxysalicylidene)-2-methylbutyl-4 0 -amino-cinnamate, 16O(OH)2MBC and N-(4-n-butyloxysalicylidene)-4 0 -n-Ketylaniline, 4O(OH)5 are presented. The advantages of PA technique are elaborated.

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