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311.
V.N. VijayakumarM.L.N. Madhu Mohan 《Physica B: Condensed Matter》2011,406(21):4139-4144
Novel homologs series of supra-molecular liquid crystals have been isolated. Hydrogen bond is formed between mandelic acid (MD) and various homologs of p-n-alkyloxy benzoic acids (nOBA) and has been confirmed by FTIR studies. Optical polarizing microscopic observations show that all these materials exhibit rich liquid crystallinity with various mesophases. Phase transition temperatures and enthalpy values are experimentally evaluated by DSC studies and the phase diagram of homologous series has been constructed. An interesting feature is the observation of thermally controlled reversible optical shuttering action in one of the homolog, wherein with the increment of temperature the homeotropic texture changes to homogenous texture of smectic F. Thus, this optical shuttering phenomenon is reversible. Optical tilt angle data of two homologs have been fitted to power law equation and it is found that the mean field theory prediction is valid. The light intensity profile in homeotropic region of smectic F in one complex has been experimentally analyzed and a steep sudden decrement of the intensity of light manifesting the distortion of the molecular alignment is experimentally found. 相似文献
312.
Mahata P Sarma D Madhu C Sundaresen A Natarajan S 《Dalton transactions (Cambridge, England : 2003)》2011,40(9):1952-1960
A hydrothermal reaction of Mn(OAc)(2)·4H(2)O, Co(OAc)(2)·4H(2)O and 1,2,4 benzenetricarboxylic acid at 220 °C for 24 h gives rise to a mixed metal MOF compound, [CoMn(2){C(6)H(3)(COO)(3)}(2)], I. The structure is formed by the connectivity between octahedral CoO(6) and trigonal prism MnO(6) units connected through their vertices forming a Kagome layer, which are pillared by the trimellitate. Magnetic susceptibility studies on the MOF compound indicate a canted anti-ferromagnetic behavior, due to the large antisymmetric DM interaction between the M(2+) ions (M = Mn, Co). Thermal decomposition studies indicate that the MOF compound forms a tetragonal mixed-metal spinel phase, CoMn(2)O(4), with particle sizes in the nano regime at 400 °C. The particle size of the CoMn(2)O(4) can be controlled by varying the decomposition temperature of the parent MOF compound. Magnetic studies of the CoMn(2)O(4) compound suggests that the coercivity and the ferrimagnetic ordering temperatures are dependent on the particle size. 相似文献
313.
314.
S. H. Jayaprakash B. Satheesh Krishna S. Santhi Sudha N. Bakthavatchala Reddy P. Sreelakshmi K. Madhu Kumar Reddy 《合成通讯》2013,43(18):2083-2091
A convenient and mild procedure is developed for β-nitrophosphonates via phospha-Michael addition of phosphites to nitrostyrene at room temperature in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU)–based ionic liquid [DBUH][OAc]. The operational simplicity, convenient workup, and reusability of the ionic liquid make this method attractive. 相似文献
315.
Kishor Muchenedi Hari Madhu Mohan M. L. N. 《The European physical journal. E, Soft matter》2023,46(2):1-8
The European Physical Journal E - Magnetorheological fluid (MRF) is a smart responsive fluid, when exposed to the magnetic field, reflects a noticeable transformation in fluid viscosity due to the... 相似文献