Chilla Malla Reddy
"One should be able to relate every physical property of a crystal to its underlying structure, if the structure-property correlation is established by carefully investigating each and every small structural factor, i.e. strength, spatial distribution and nature of interactions. The FleXtal Lab's motivation is to make mechanical behavior of organic single crystals predictable and designable by using Crystal Engineering approach."
Dr. C Malla Reddy did his Ph.D. in Supramolecular Chemistry & Crystal engineering from the University of Hyderabad in 2006. There after he continued his research as a post-doctoral fellow at Karlsruhe Institute of Technology, Germany, 2007-2008. Immediately he moved to Indian Institute of Science Education and Research (IISER) Kolkata as an assistant professor in department of chemical sciences. In 2014 he has been promoted to associate professor. Then In 2019 he has been promoted to professor. For the Year 2014-2015, he has been awarded with prestigious Swarna Jayanti fellowship by Department of science and technology, Goverment of India.
Research Areas: • Crystal Engineering & Supramolecular Chemistry • Design of Flexible Organic Functional Materials • Solid-State Pharmaceutical Chemistry (Tabletability) • Structure-Mechanical Property Relationship
The focus of our research group is to design the properties of organic materials by establish a reliable structure-property correlationship. Our current major projects include (i) the understanding of structure-mechanical property relationship in flexible organic crystals (ii) design of new solid forms of active pharmaceutical ingredients (APIs) with improved mechanical behaviour and tabletability, (iii) establishing design principles for efficient mechanochromic luminescent solid state fluorophores. The general characterization techniques we use include nanoindentation, hot-stage microscopy, Raman spectroscopy, powder and single crystal x-ray diffraction, TGA, DSC, SEM, TEM etc.
Awards and Honors:
Some Selected Publications:
Reasearch Projects :
Mechanically Flexible Organic Crystals Achieved by Introducing Weak Interactions in Structure: Supramolecular Shape Synthons c&en chemical & engineering news
CRYSTAL CONTORTIONISTS: MAKING FLEXIBLE ORGANIC CRYSTALS: Organic crystals have a variety of useful characteristics that confer advantages over their inorganic counterparts for applications such as transistors, solar cells, photonics, and bioelectronics. However, the brittle nature of these organic materials significantly limits their use in any device that requires flexibility. C. Malla Reddy and colleagues report a way to engineer organic crystals to make them extremely bendable to the extent that they are able to contort into different letters of the alphabet (DOI: 10.1021/jacs.6b05118).
New method for making flexible single crystals: The crystals can respond to external stimuli such as mechanical stress, light and heat, they could be used to make pressure sensors and mechanical actuators,” says lead scientist Chilla Malla Reddy from the Indian Institute of Science Education and Research, Kolkata. Nature India
Research News :
Elastic caffeine crystals Nature Chemistry
Caffeine crystals with an elastic bent Chemistry World
Molecular motors from bendable organic crystal Nature India
Some highlights of the published work :
Different crystal shapes achieved by mechanical stress on BH3NMe3 (a-l), BF3NMe3 (m-q) and BH3NHMe2 (r, s). a) Coiling. b) Twist-coiling. c) Thinning followed by rolling. d) Spring and its elongation. e) Double helix. f) Twisting. g) Compression. h) Stretching. i) Necking. j) Enlarged view of necking region. k) and l) First two alphabets of Bengali and Telugu dialects, respectively. m) Spring shape. n) Ampersand. o) Single helix tied to a glass capillary. p) and q) Full and partial thinning, respectively. r) Brittle fracture on one face and s) 1D plastic bending on another face in BH3NHMe2 crystals.
Chemical structures (i), (ii) and (iii) of the compounds (1), molecular crystals of the three individual compounds illuminated under UV (2), their qualitative deformation behaviour upon mechanical action (3), and mechanochromic luminescence behaviour of the crystals upon smearing (4). In column 4, (a), (d) and (g) show the UV (365 nm) emission colour of initial powder ﬁlms prepared by gently grinding single crystals of the three samples using a mortar and pestle. Images (b), (e) and (h) correspond to the ﬁlms after ﬁrmly scratching the initial ﬁlms with a pestle, resulting in a colour change from cyan to yellow for BF2dbm(tBu)2 and green to yellow for BF2dbm(OMe)2 while no colour change was observed for BF2dbmOMe at room temperature (h), respectively. For both BF2dbm(tBu)2 and BF2dbm(OMe)2 compounds, the ﬁlms recover to the parent colour shown in (c) and (f) after a few minutes of heating with a hot-air gun. In the case of BF2dbmOMe the ML experiments were repeated at 98C by immersing the mortar into frozen methanol by cooling wth liquid N2 (g), but no signiﬁcant colour change was observed in (h) and (i).for more..