Synthesis and spectral/structural elucidation of new organic materials for non-linear optical and electro-optical applications
Aim
Modern information technology requires new methods for data processing to save acquired data and to transfer these rapidly. One approach to meet this goal is the development of materials with non-linear optical properties, which enables industry to develop, for instance, new screens with unique resolution. Organic materials are, in contrast to the common inorganic materials, a reasonable alternative.
Squaric acid is a dibasic acid that has two acidic hydroxyl-groups with pKa values of 0.54 and 3.48 as well as two highly polarized carbonyl groups. This unique structure provides not only proton acceptor sites at the carbonyl functions for hydrogen bonding with other molecules but also binding sites to divalent metal ions.
Condensation products of diethylsquarate and optically active free bases of amino acid amides play a very important role as NLO materials. Some of them such like L-argininium hydrogensquarate and L-argininum dihydrogenphosphate have been used as promising materials for frequency conversion.
Approach
We have synthesized the following new materials with non-linear optical properties (Fig. 30).
Figure 30: Synthesized materials with non-linear optical properties
Results
5-Amino-2-methoxypyridine amide of squaric acid crystallizes in the noncentrosymmetric space group Cc without using chiral agents. The electronic nonlinearity of this push-pull system is based on molecular units containing a delocalized p-electron system with donor and acceptor groups at opposite ends of the molecule. The molecule belongs to the class of two-dimensional quadrupoles such as 4,6-dinitroresorcin. Its being a NLO quadrupole and containing an N(pyridine atom) which is a potential centre for conversion to a corresponding pyridinium-betaine derivative. Its pseudo layer structure could enable the inclusion of small molecules between the layers, which could be used for catalysis as well.
Funding
German Academic Exchange Service (DAAD) within the program Stability Pact for South-East-European Countries
Contact
Prof. Dr. Tsonko Kolev
Bulgarian Academy of Sciences
kolev@orgchm.bas.bg
Phone: +35 (92) 9606106
Univ.-Prof. Dr. Dr. h.c. Michael Spiteller
M.Spiteller@infu.uni-dortmund.de
Phone: +49-(0)231-755-4080
Paper
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Kolev, T.; Koleva, B. B.; Spiteller, M.; Sheldrick, W. S.; Mayer-Figge, H. (2007):
"Synthesis, Spectroscopic and Structural elucidation of Sympathomimetic Amine, Tyraminium Dihydrogenphosphate"
Amino Acids submitted.
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Kolev, T.; Koleva, B.B.; Emgenbroich, M. ; Spiteller, M. ; Sheldrick, W.S. ; Mayer-Figge, H. (2006):
"Crystal structure and linear-dichroic infrared (IR-LD) spectral analysis of N,N'-diethyl-4-vinylbenzamidinium squarate"
Struct. Chem., 17, 631-637.
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Kolev, T.; Koleva, B. B.; Cherneva,E.; Spiteller, M.; Sheldrick, W. S.; Mayer-Figge, H. (2007):
"Synthesis, spectroscopic and structural elucidation of 5-amino-2-methoxypyridine ester amide of squaric acid ethyl ester: a new material with infinite layered structure"
Spectrochimica Acta Part A, 68, 1187-1196.
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Kolev, T.; Koleva, B. B.; Spiteller, M.; Sheldrick, W. S.; Mayer-Figge, H. (2008):
"Benzamidinium D-glucuronate: spectroscopic and structural elucidation"
Journal of Molecular Structure, 879, 30-39.
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Kolev, T.; Spiteller, M. (2005):
"Bis(8-hydroxyquinolinium) squarate"
Acta Cryst., E 61, o1469-o1471.
more informations...
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Kolev, T.; Spiteller, M.; Mayer-Figge, H.; Sheldrick, W. S. (2006):
"Benzamidinium dihydrogenphosphate"
Acta Crystallographica Section E, Structure Reports Online, E63, o1016-o1018.
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Kolev, T.; Spiteller, M.; Sheldrick, W. S.; Mayer-Figge, H. (2006):
"Synthesis, spectroscopic and structural elucidation of 2-amino-4-nitroaniline: Potential material for nonlinear optical application"
Adv. Func. Mater. submitted.
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Kolev, T.; Wortmann, R.; Spiteller, M.; Sheldrick, W.S.; Mayer-Figge, H. (2005):
"4-Phenylphyridinium betaine of squaric acid"
Acta Cryst., E61, o1090-o1092.
more informations...
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Kolev, T.; Yancheva, D.; Shivachev, B.; Petrova, R.; Spiteller, M. (2005):
"2-{3-[(E)-(3,4-Dimethoxyphenyl)ethenyl]-5,5-dimethylcyclohexyl-2-enylidene}malononitrile"
Acta Cryst., E 61, o550-o552.
more informations...
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Kolev, T.; Yancheva, D.; Shivachev, B.; Petrova, R.; Spiteller, M. (2005):
"2-(3-Benzoyl-1-pyridinio)-3,4-dioxocyclobutenolate"
Acta Cryst., C 61, o213-o215.
more informations...