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Maranda-Niedbała A, Jaroch T, Walker R, Pięta P, Górecka E, Imrie CT, Storey JMD, Proń A, Nowakowski R. Supramolecular Organization in Monolayers of Pyrene-Functionalized Asymmetric Twist-Bend Nematic Dimers: Comparison with a Three-Dimensional Crystal Structure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2025; 41:9508-9519. [PMID: 40173290 PMCID: PMC12004918 DOI: 10.1021/acs.langmuir.5c00551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2025] [Revised: 03/12/2025] [Accepted: 03/24/2025] [Indexed: 04/04/2025]
Abstract
Two-dimensional (2D) supramolecular organization of asymmetric liquid crystal dimers containing two chemically different mesogenic groups, namely, cyanobiphenyl and pyreneiminomethyl phenoxy groups, linked with an oligomethylene linker of different length (six or eight -CH2- units), was studied using scanning tunneling microscopy. For this purpose, monolayers of these dimers were deposited on an HOPG substrate from their solutions in hexane by drop-casting and imaged at nanometer resolution after drying. A detailed discussion of two possible different supramolecular organizations is presented. In the case of the first one, termed the "lamellar structure", the molecules in each layer are arranged in parallel molecular rows. Comparative analysis of the monolayer structure with already reported XRD data on 3D organization of the same molecules in a single crystal revealed significant differences resulting from (i) different ordering preferences in 2D and 3D systems and (ii) effects of the interactions of the deposited molecules with the graphite substrate. A small extension of the linker by two methylene groups does not change the type of ordering in the monolayer but causes an extension of the unit cell in one direction, indicating that the lamellar structure is stabilized by rows of densely packed large aromatic pyrene units. Studies of the derivative with a longer linker (containing eight -CH2- units) also showed the possibility of the occurrence of an alternative type of its monolayer organization, termed here "aggregate structure". In this case, the monolayer consists of ordered aggregates of two molecules. According to the authors' knowledge, this type of structural organization has not yet been reported for this family of compounds. It is, however, qualitatively consistent with the already described supramolecular ordering in CBO5O.Py (CCDC 2019485), a compound closely resembling the dimers studied in this research.
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Affiliation(s)
| | - Tomasz Jaroch
- Faculty
of
Chemistry, Warsaw University of Technology, Noakowskiego 3, Warszawa 00-664, Poland
| | - Rebecca Walker
- Department
of Chemistry, University of Aberdeen, UK3G28 Meston Building, Old Aberdeen
Campus, Meston Walk, Aberdeen AB24 3UE, U.K.
| | - Piotr Pięta
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warszawa 01-224, Poland
| | - Ewa Górecka
- Department
of Chemistry, University of Warsaw, Żwirki i Wigury 101, Warszawa 02-089, Poland
| | - Corrie T Imrie
- Department
of Chemistry, University of Aberdeen, UK3G28 Meston Building, Old Aberdeen
Campus, Meston Walk, Aberdeen AB24 3UE, U.K.
| | - John MD Storey
- Department
of Chemistry, University of Aberdeen, UK3G28 Meston Building, Old Aberdeen
Campus, Meston Walk, Aberdeen AB24 3UE, U.K.
| | - Adam Proń
- Faculty
of
Chemistry, Warsaw University of Technology, Noakowskiego 3, Warszawa 00-664, Poland
| | - Robert Nowakowski
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warszawa 01-224, Poland
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Bendaoud U, Bhowmik PK, Chen SL, Han H, Cox SL, Liebsch J, Ros MB, Selvi Velayutham T, Aripin NFK, Martinez-Felipe A. Modulating the Conductivity of Light-Responsive Ionic Liquid Crystals. Molecules 2024; 29:4459. [PMID: 39339454 PMCID: PMC11434579 DOI: 10.3390/molecules29184459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2024] [Revised: 09/14/2024] [Accepted: 09/16/2024] [Indexed: 09/30/2024] Open
Abstract
In this work, we describe the phase behaviour and the dielectric and conductivity response of new light-responsive ionic liquid crystals, ILCs, which can be applied as controllable electrolytes. The materials include two different dicationic viologens, the asymmetric 6BP18 and the symmetric EV2ON(Tf)2, containing bistriflimide as the counterions, mixed with 5% and 50% molar, respectively, of one new photoresponsive mesogen called CNAzO14. These mixtures exhibit liquid crystal behaviour, light responsiveness through the E-Z photoisomerisation of the azobenzene groups in CNAzO14, and strong dielectric responses. The 5%-CNAzO14/Ev2ON(Tf)2 mixture displays direct current conductivities in the 10-7 S·cm-1 range, which can be increased by a two-fold factor upon the irradiation of UV light at 365 nm. Our findings set the grounds for designing new smart ionic soft materials with nanostructures that can be tuned and used for energy conversion and storage applications.
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Affiliation(s)
- Umama Bendaoud
- Chemical Processes and Materials Research Group, Just Transition Lab, Centre for Energy Transition, School of Engineering, University of Aberdeen, King’s College, Aberdeen AB24 3UE, UK; (U.B.); (J.L.)
| | - Pradip K. Bhowmik
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154, USA; (P.K.B.); (S.L.C.); (H.H.); (S.L.C.)
| | - Si L. Chen
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154, USA; (P.K.B.); (S.L.C.); (H.H.); (S.L.C.)
| | - Haesook Han
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154, USA; (P.K.B.); (S.L.C.); (H.H.); (S.L.C.)
| | - Seonghyeok L. Cox
- Department of Chemistry and Biochemistry, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Box 454003, Las Vegas, NV 89154, USA; (P.K.B.); (S.L.C.); (H.H.); (S.L.C.)
| | - Jasmin Liebsch
- Chemical Processes and Materials Research Group, Just Transition Lab, Centre for Energy Transition, School of Engineering, University of Aberdeen, King’s College, Aberdeen AB24 3UE, UK; (U.B.); (J.L.)
- Department of Chemistry, University of Aberdeen, King’s College, Aberdeen AB24 3UE, UK
| | - M. Blanca Ros
- Instituto de Nanociencia y Materiales de Aragón, Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Zaragoza-CSIC, Campus San Francisco, E-50009 Zaragoza, Spain;
| | - Thamil Selvi Velayutham
- Low Dimensional Materials Research Center, Department of Physics, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia;
| | - Nurul Fadhilah Kamalul Aripin
- School of Chemical Engineering, College of Engineering, Universiti Teknologi MARA, Shah Alam 40450, Malaysia;
- Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, King’s College, Aberdeen AB24 3UE, UK
| | - Alfonso Martinez-Felipe
- Chemical Processes and Materials Research Group, Just Transition Lab, Centre for Energy Transition, School of Engineering, University of Aberdeen, King’s College, Aberdeen AB24 3UE, UK; (U.B.); (J.L.)
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