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Punjani V, Mohiuddin G, Kaur S, Choudhury AR, Paladugu S, Dhara S, Ghosh S, Pal SK. Chiral Bent-Shaped Molecules Exhibiting Unusually Wide Range of Blue Liquid-Crystalline Phases and Multistimuli-Responsive Behavior. Chemistry 2020; 26:5859-5871. [PMID: 32083772 DOI: 10.1002/chem.201905707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/02/2020] [Indexed: 11/11/2022]
Abstract
Recently, an unprecedented observation of polar order, thermochromic behavior, and exotic mesophases in new chiral, bent-shaped systems with a -CH3 moiety placed at the transverse position of the central core was reported. Herein, a homologous series of compounds with even-numbered carbon chains from n=4 to 18 were synthesized, in which -Cl was substituted for -CH3 at the kink position and a drastic modification in the phase structure of the bent-shaped molecule was observed. An unusual stabilization of the cubic blue phase (BP) over a wide range of 16.4 °C has been witnessed. Two homologues in this series (1-12 and 1-14) exhibit an interesting phase sequence consisting of BPI/II, chiral nematic, twist grain boundary, smectic A, and smectic X (SmX) phases. The higher homologues (1-16 and 1-18) stabilize the SmX phase enantiotropically over the entire temperature range. Crystal structure analysis confirmed the bent molecular architecture, with a bent angle of 148°, and revealed the presence of two different molecular conformations in an asymmetric unit of compound 1-4. A DFT study corroborated that the -Cl moiety at the central core of the molecule led to an increase in the dipole moment along the transverse direction, which, in turn, facilitated the unusual stabilization of frustrated structures. Crystal polymorphism has been evidenced in three homologues (1-10, 1-12, and 1-14) of the series. On the application of mechanical pressure through grinding, compound 1-10 transformed from a bright yellow crystalline solid to a dark orange-green amorphous solid, which reversed upon dropwise addition of dichloromethane, indicating reversible mechanochromism in this class of compounds. In addition, excellent thermochromic behavior has been observed for compound 1-10 with a controlled temperature-color combination.
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Affiliation(s)
- Vidhika Punjani
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli, 140306, India
| | - Golam Mohiuddin
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli, 140306, India
| | - Supreet Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli, 140306, India
| | - Angshuman Roy Choudhury
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli, 140306, India
| | | | - Surajit Dhara
- School of Physics, University of Hyderabad, Hyderabad, 500046, India
| | - Sharmistha Ghosh
- Department of Physics, University of Calcutta, 92 Acharyya Prafulla Chandra Road, Kolkata, 700009, India
| | - Santanu Kumar Pal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Knowledge City, Manauli, 140306, India
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Liu K, Pesce D, Ma C, Tuchband M, Shuai M, Chen D, Su J, Liu Q, Gerasimov JY, Kolbe A, Zajaczkowski W, Pisula W, Müllen K, Clark NA, Herrmann A. Solvent-free liquid crystals and liquids based on genetically engineered supercharged polypeptides with high elasticity. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:2459-2465. [PMID: 25732045 DOI: 10.1002/adma.201405182] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 02/11/2015] [Indexed: 06/04/2023]
Abstract
A series of solvent-free elastin-like polypeptide liquid crystals and liquids are developed by electrostatic complexation of supercharged elastin-like polypeptides with surfactants. The smectic mesophases exhibit a high elasticity and the values can be easily tuned by varying the alkyl chain lengths of the surfactants or the lengths of the elastin-like polypeptides.
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Affiliation(s)
- Kai Liu
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747, AG, Groningen, The Netherlands
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