@article { ISI:000286868600075, title = {Toward an understanding of the molecular level properties of ziegler-natta catalyst support with and without the internal electron donor}, journal = {Journal of Physical Chemistry C}, volume = {115}, number = {5}, year = {2011}, month = {FEB}, pages = {1952-1960}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Two Ziegler-Natta catalysts supported on molecular adducts, namely, MgCl2 center dot 6EtOH (ME) and MgCl2 center dot 5EtOH center dot EtOOCPh (Est-ME), have been prepared. A systematic effort has been made to unravel the molecular level structure property relationships of the catalysts and adducts. Ethylbenzoate is an internal electron donor, and its in situ formation through EtOH+PhCOCl coupling is successfully achieved. The above adduct has been treated with TiCl4, and the resultant catalyst (Ti/Est-ME) is evaluated for ethylene polymerization activity. Rand C-13 CP/MAS NMR of Est-ME (Ti/Est-ME) show carbonyl features at 1730 (1680) cm(-1) and 169 (170) delta, respectively, providing direct support for the presence of ester as an integral part. In spite of low surface area, Ti/Est-ME gives higher yield for ethylene polymerization than the one derived from ME. The results indicate that electronic environment is more important than surface area or any other single factor in determining the polymerization activity.

}, issn = {1932-7447}, doi = {10.1021/jp1078289}, author = {Thushara, K. S. and Gnanakumar, Edwin S. and Mathew, Renny and Jha, Ratnesh Kumar and Ajithkumar, Thalasseril G. and Rajamohanan, P. R. and Sarma, Krishna and Padmanabhan, Sudhakar and Bhaduri, Sumit and Gopinath, Chinnakonda S.} } @article { ISI:000352463200009, title = {Total synthesis and structural revision of mycalol, an anticancer natural product from the marine source}, journal = {Organic Letters}, volume = {17}, number = {7}, year = {2015}, month = {APR}, pages = {1652-1655}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The total synthesis of an anticancer (anaplastic thyroid) natural lipid mycalol has been accomplished for the first time. Synthesis of originally proposed structure necessitated the revision of structure in which the position of acetate group moved from C20 to C19 and a change in stereochemistry of the glycerol unit.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.5b00345}, author = {Seetharamsingh, B. and Rajamohanan, P. R. and Reddy, D. Srinivasa} } @article {44480, title = {Thermo thickening behavior of MPEG-b-PCL grafted poly(acrylic acid): a molecular insight}, journal = {Polymer}, volume = {148}, year = {2018}, month = {JUL}, pages = {138-148}, type = {Journal Article}, abstract = {

We report on the synthesis and characterization of a new thermothickening polymer (PAA-g-(MPEG-b-PCL)) based on the grafting of a block copolymer of mono methoxy poly (ethylene glycol){\textendash}b-poly (caprolactone) (MPEG-b-PCL) onto poly (acrylic acid) (PAA). Rheological experiments reveal that aqueous solutions of PAA-g-(MPEG-b-PCL) exhibit interesting irreversible thermothickening behavior above a certain polymer concentration and critical temperature. Light scattering experiments show that increasing temperature induces hydrophobic associations and subsequent aggregation leading to gel formation which is irreversible. The mechanism of thermo thickening was examined at the molecular level by NMR methods which indicated unassembled and assembled environments of the MPEG-b-PCL grafts. On heating, interactions between the graft side chains are significantly enhanced and molecular mobility in the assembled microdomains is reduced. The stable well ordered microdomains that are formed on heating are retained on cooling thus, leading to irreversible gelation.

}, keywords = {Hydrophobically modified poly (acrylic acid), Light scattering, Methoxy polyethylene glycol-b-polycaprolactone (MPEG-b-PCL) copolymer, Rheology, Thermo gelation}, issn = {323861}, doi = {10.1016/j.polymer.2018.06.031}, author = {Tiwari, Neha}, editor = {Shedge, Aarti} }