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Blanco H, Iguarbe V, Barberá J, Serrano JL, Elduque A, Giménez R. Supramolecular Columnar Liquid Crystals with Tapered-Shape Simple Pyrazoles Obtained by Efficient Henry/Michael Reactions. Chemistry 2016; 22:4924-30. [PMID: 26890692 DOI: 10.1002/chem.201504779] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Indexed: 11/10/2022]
Abstract
A straightforward synthesis of mesogenic pyrazoles starting from benzaldehydes by a combination of efficient Henry and Michael reactions led to novel supramolecular liquid crystals. The mesogens are fluorescent 3,5-dimethyl-4-(di or trialkoxyphenyl)pyrazoles and, in spite of the tapered shape of these molecules and their structural simplicity (only one phenyl ring), columnar liquid-crystal phases were formed that are stable at room temperature. The self-assembled structure was studied by XRD and the columnar cross section contains two molecules on average with an antiparallel arrangement of pyrazoles interacting through hydrogen bonds. In contrast, the single-crystal structure of a trimethoxy analog did not show hydrogen-bonded pyrazoles but chains of head-to-tail arranged molecules.
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Affiliation(s)
- Hugo Blanco
- Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Verónica Iguarbe
- Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - Joaquín Barberá
- Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain
| | - José Luis Serrano
- Dpto de Química Orgánica, Facultad de Ciencias, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018, Zaragoza, Spain
| | - Anabel Elduque
- Dpto de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
| | - Raquel Giménez
- Instituto de Ciencia de Materiales de Aragón (ICMA), Dpto de Química Orgánica, Facultad de Ciencias, CSIC-Universidad de Zaragoza, 50009, Zaragoza, Spain.
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Affiliation(s)
- Julio Pérez
- Departamento de Química Orgánica e Inorgánica‐IUQOEM, Facultad de Química, Universidad de Oviedo‐CSIC, 33006 Oviedo, Spain, Fax: +34‐985103446
| | - Lucía Riera
- Departamento de Química Orgánica e Inorgánica‐IUQOEM, Facultad de Química, Universidad de Oviedo‐CSIC, 33006 Oviedo, Spain, Fax: +34‐985103446
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Giménez R, Elduque A, López JA, Barbera J, Cavero E, Lantero I, Oro LA, Serrano JL. Supramolecular Structures and Columnar Mesophase Induction in Nondiscoid Pyrazoles by Complexation to Rhodium(I). Inorg Chem 2006; 45:10363-70. [PMID: 17140246 DOI: 10.1021/ic0614216] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several new cis-[RhCl(CO)2(Ln)] complexes have been prepared using different polycatenar pyrazole ligands (Ln) in order to obtain columnar liquid crystalline arrangements. The topology of the ligand plays an essential role, and a mesophase is induced at room temperature from a nonmesogenic pyrazole only when it is symmetrically substituted with six decyloxy chains. The single-crystal structure of a methoxy-substituted analogue, 3,5-bis(3,4,5-trimethoxyphenyl)pyrazole, is formed by globular tetrameric structures held together by H-bonding. However, parallel dimers are present in the corresponding cis-chlorodicarbonylrhodium(I) complex, a situation that explains the induction of a columnar mesophase in the decyloxy-substituted complex. The XRD pattern of the mesophase is consistent with a hexagonal symmetry in which the columns are formed by molecules assembled in an antiparallel mode. The crystal-to-mesophase transition was also detected by spectroscopic techniques as a shift in the IR carbonyl stretching bands and the appearance of a charge-transfer band in the absorption spectrum with thermochromic behavior.
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Affiliation(s)
- Raquel Giménez
- Departamento de Química OrgAnica, Facultad de Ciencias-Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain.
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Song YH, Chi Y, Chen YL, Liu CS, Ching WL, Carty AJ, Peng SM, Lee GH. A Study of Unsaturated Pyrazolate-Bridged Diruthenium Carbonyl Complexes. Organometallics 2002. [DOI: 10.1021/om020445r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yi-Hwa Song
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Yun Chi
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Yao-Lun Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Chao-Shiuan Liu
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Wei-Li Ching
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Arthur J. Carty
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Shie-Ming Peng
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
| | - Gene-Hsiang Lee
- Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada, and Department of Chemistry and Instrumentation Center, National Taiwan University, Taipei 10764, Taiwan, Republic of China
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