Design and Synthesis of Microporous Dipeptide Structures and Guanidinium-carboxylate-based Organic Supramolecular Materials
Appears in the following Collection
- Kjemisk institutt 
AbstractThe basis of supramolecular chemistry is a detailed knowledge of fundamental molecular properties and non-covalent interactions, which is dedicated to the preparation of novel structures as functional materials. Here we discuss the design and synthesis of such new molecular self-assemblies. Based on the structures and properties of these molecules, this dissertation describes the two types of supramolecular structures in two different chapters.
Chapter 1 deals with the design, preparation, characterization and applications of chiral, bio-degradable, guest-specific and environment-friendly nanoporous crystalline dipeptides. In the hydrogen-bonded networks, dipeptides with hydrophobic L-amino acid residues are known to form pores of different diameters, ranging from 3-10 Å. The hydrophobic bulk and orientations of the side chains of these dipeptides provide further scope for structure-based modifications to fine-tune their pore dimensions. Thus, towards the liberation of space occupied by bulky hydrophobic terminals of the amino acid side chains from the periphery of channels, a series of dipeptides from non-proteinogenic and proteinogenic amino acids have been synthesized, crystallized and analyzed by single crystal X-ray diffraction methods. The majority of these dipeptides were obtained as porous structures. As nanoporous materials, a few of these dipeptides were studied for CO2 and methane gas absorption and selectivity.
Chapter 2 demonstrates the supramolecular synthesis of charge-assisted complexes from binary acid-base components. The well-directed hydrogen bond formation between acids and bases is a very useful tool in designing new supramolecular assemblies. Here we pursued an approach to use 1,5,7 triazabicyclo[4.4.0]-dec-5-ene, a guanidine derivative, with di- or monocarboxylic acids to generate guanidinium-carboxylate complexes. These molecular structures were designed to explore the effects of limited hydrogen-bond forming ability of guanidinium moiety and carboxylate group, and to check the propensity of guanidinuimcarboxylate complexes for the inclusion of guest molecules, for instance the water molecules. In fact, these complexes in crystals have interacted with the water molecules or carboxyl groups in the absence of any other potential donors and formed different water networks and 1D molecular pattern, which as organic materials may find various future applications as proton conductors, selective ion channels and gelators etc.
List of papers. The papers are removed from the thesis due to publisher restrictions.
I) Porous Organic Materials from Dipeptides with Non-proteinogenic Residues Vitthal N. Yadav, Carl Henrik Görbitz, Tore-Boge Hansen, Angiolina Comotti and Piero Sozzani, (2013), (Manuscript Submitted to JACS).
II) A Water Wire in L-prolyl-L-serine Hydrate Carl Henrik Görbitz and Vitthal N. Yadav, (2013), Acta. Cryst. C69, 556-559. doi:10.1107/S0108270113010299
III) An Unexpected Tetragonal Unit Cell for N-(L-2-aminobutyryl)-L-serine Carl. Henrik Görbitz and Vitthal N. Yadav, (2013), Acta. Cryst. C69, 888-891. doi:10.1107/S0108270113017484
IV) N-(L-2-Aminopentanoyl)-L-phenylalanine Dihydrate, a Hydrophobic Dipeptide with a Nonproteinogenic Residue Carl Henrik Görbitz and Vitthal N. Yadav, (2013), Acta. Cryst. C69, 1067-1069. doi:10.1107/S0108270113021914
V) A Supramolecular 2 : 1 Guanidinium-carboxylate Based Building Block for Generation of Water Channels and Clusters in Organic Materials Vitthal N. Yadav and Carl Henrik Görbitz, (2013), CrystEngComm, 15, 439-442, (*Hot Article, RSC, Nov. 2012). doi:10.1039/c2ce26572a
VI) Water of Hydration in 2:1 Hydrogen Bonded Complexes Between 1,5,7 triazabicyclo[4.4.0]-dec-5-ene and Dicarboxylic acids Vitthal N. Yadav and Carl Henrik Görbitz, (2013), Crystal Growth & Design, 13, 2174-2180. doi:10.1021/cg400250n
VII) Supramolecular 1D Ribbons from Bicyclic Guanidine Derivative and Di- or Monomonocarboxylic acids Vitthal N. Yadav and Carl Henrik Görbitz, (2013), CrystEngComm, 15, 7321- 7326. (*Hot Article, RSC, Aug. 2013). doi:10.1039/c3ce40960k