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Tuning the Liquid Crystallinity of Cholesteryl-o-Carborane Dyads: Synthesis, Structure, Photoluminescence, and Mesomorphic Properties. CRYSTALS 2021. [DOI: 10.3390/cryst11020133] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A set of mesomorphic materials in which the o-carborane cluster is covalently bonded to a cholesteryl benzoate moiety (mesogen group) through a suitably designed linker is described. The olefin cross-metathesis between appropriately functionalized styrenyl-o-carborane derivatives and a terminal alkenyl cholesteryl benzoate mesogen (all type I terminal olefins) leads to the desired trans-regioisomer, which is the best-suited configuration to obtain mesomorphic properties in the final materials. The introduction of different substituents (R = H (M2), Me (M3), or Ph (M4)) to one of the carbon atoms of the o-carborane cluster (Ccluster) enables the tailoring of liquid crystalline properties. Compounds M2 and M3 show the chiral nematic (N*) phase, whereas M4 do not show liquid crystal behavior. Weaker intermolecular interactions in the solid M3 with respect to those in M2 may allow the liquid crystallinity in M3 to be expressed as enantiotropic behavior, whereas breaking the stronger intermolecular interaction in the solid state of M2 leads directly to the isotropic state, resulting in monotropic behavior. Remarkably, M3 also displays the blue phase, which was observed neither in the chiral nematic precursor nor in the styrenyl-cholesterol model (M5) without an o-carborane cluster, which suggests that the presence of the cluster plays a role in stabilizing this highly twisted chiral phase. In the carborane-containing mesogens (M2 and M3), the o-carborane cluster can be incorporated without destroying the helical organization of the mesophase.
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An efficient synthesis of carboranyl tetrazoles via alkylation of 5-R-1H-tetrazoles with allylcarboranes. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.05.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Jankowiak A, Kaszyński P. Practical Synthesis of 1,12-Difunctionalized o-Carborane for the Investigation of Polar Liquid Crystals. Inorg Chem 2014; 53:8762-9. [DOI: 10.1021/ic5014494] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aleksandra Jankowiak
- Organic Materials
Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Piotr Kaszyński
- Organic Materials
Research Group, Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Section of Heteroorganic Compounds, University of Łódź, Tamka 12, 91403 Łódź, Poland
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Ringstrand B, Kaszynski P. High Δε nematic liquid crystals: fluxional zwitterions of the [closo-1-CB9H10]−cluster. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c0jm02075c] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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General Access to Aminobenzyl-o-carboranes as a New Class of Carborane Derivatives: Entry to Enantiopure Carborane-Amine Combinations. Chemistry 2009; 15:12030-42. [DOI: 10.1002/chem.200901332] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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