Quasi Single-crystalline Transformation of Porous Frameworks Accompanied with Interlayer Rearrangements of Hydrogen Bonds

2021 ◽  
Author(s):  
Haruka Kubo ◽  
Ryusei Oketani ◽  
Ichiro Hisaki

Quasi single-crystal-to-single-crystal transformation of a hydrogen-bonded organic framework (HOF) was accurately revealed and the mechanism was proposed. Interestingly, Br/π interaction allows to solve the crystal structure of intermediate phase as...

2005 ◽  
Vol 61 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Stephen A. Moggach ◽  
David R. Allan ◽  
Carole A. Morrison ◽  
Simon Parsons ◽  
Lindsay Sawyer

The crystal structure of L-serine has been determined at room temperature at pressures between 0.3 and 4.8 GPa. The structure of this phase (hereafter termed L-serine-I), which consists of the molecules in their zwitterionic tautomer, is orthorhombic, space group P212121. The least compressible cell dimension (c), corresponds to chains of head-to-tail NH...carboxylate hydrogen bonds. The most compressible direction is along b, and the pressure-induced distortion in this direction takes the form of closing up voids in the middle of R-type hydrogen-bonded ring motifs. This occurs by a change in the geometry of hydrogen-bonded chains connecting the hydroxyl groups of the —CH2OH side chains. These hydrogen bonds are the longest conventional hydrogen bonds in the system at ambient pressure, having an O...O separation of 2.918 (4) Å and an O...O...O angle of 148.5 (2)°; at 4.8 GPa these parameters are 2.781 (11) and 158.5 (7)°. Elsewhere in the structure one NH...O interaction reaches an N...O separation of 2.691 (13) Å at 4.8 GPa. This is amongst the shortest of this type of interaction to have been observed in an amino acid crystal structure. Above 4.8 GPa the structure undergoes a single-crystal-to-single-crystal phase transition to a hitherto uncharacterized polymorph, which we designate L-serine-II. The OH...OH hydrogen-bonded chains of L-serine-I are replaced in L-serine-II by shorter OH...carboxyl interactions, which have an O...O separation of 2.62 (2) Å. This phase transition occurs via a change from a gauche to an anti conformation of the OH group, and a change in the NCαCO torsion angle from −178.1 (2)° at 4.8 GPa to −156.3 (10)° at 5.4 GPa. Thus, the same topology appears in both crystal forms, which explains why it occurs from one single-crystal form to another. The transition to L-serine-II is also characterized by the closing-up of voids which occur in the centres of other R-type motifs elsewhere in the structure. There is a marked increase in CH...O hydrogen bonding in both phases relative to L-serine-I at ambient pressure.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Xiang-Yu Gao ◽  
Yu-Lin Li ◽  
Tianfu Liu ◽  
Xinsong Huang ◽  
Rong Cao

The design and synthesis of a hydrogen-bonded organic framework (HOF) based on tetrathiafulvalene tetracarboxylic acid is reported. The resultant HOF can undergo single-crystal-to-single-crystal transformation to form another two isomers. The...


2016 ◽  
Vol 52 (63) ◽  
pp. 9781-9784 ◽  
Author(s):  
Ichiro Hisaki ◽  
Shoichi Nakagawa ◽  
Hiroyasu Sato ◽  
Norimitsu Tohnai

A hydrogen-bonded low-density organic framework achieved periodic alignment of paired molecules of C60.


2007 ◽  
Vol 72 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Goran Bogdanovic ◽  
Vukadin Leovac ◽  
Ljiljana Vojinovic-Jesic ◽  
Biré-Spasojevic De

The crystal structure of [CoIII(L)(py)3][CoIICl3(py)] (H2L=salicylaldehyde semicarbazone)was determined by X-ray analysis based on two single crystal X-ray experiments performed at 120 K and 293 K, respectively. It was found that the pyridine ligand of the complex anion is disordered over two positions. The preferential position of this pyridine found at120Kwas explained in terms of the C-H...Cl intermolecular interaction between the tetrahedral [CoII(py)Cl3]- anions. The mer-octahedral geometry of the cation in the presented crystal structure was compared with previously published structures of similar composition, [CoIII(L1)(py)3]+[CoIICl3(py)]-?EtOH and [CoIII(LI)(py)3]+I3-(H2LI = salicylaldehyde S-methylisothiosemicarbazone). Although the tetrahedral [CoIICl3(py)]- anions possess the same charge, they mutually form different intermolecular interactions which can be realized either by C-H...Cl hydrogen bonds or by ?-? interactions between the pyridine rings.


Author(s):  
Feodor Belov ◽  
Alexander Villinger ◽  
Jan von Langermann

This article provides the first single-crystal XRD-based structure of enantiopure (R)-baclofen (form C), C10H12ClNO2, without any co-crystallized substances. In the enantiopure title compound, the molecules arrange themselves in an orthorhombic crystal structure (space group P212121). In the crystal, strong hydrogen bonds and C—H ... Cl bonds interconnect the zwitterionic molecules.


2018 ◽  
Vol 74 (8) ◽  
pp. 1159-1162
Author(s):  
Ramalingam Sangeetha ◽  
Kasthuri Balasubramani ◽  
Kaliyaperumal Thanigaimani ◽  
Savaridasson Jose Kavitha

In the title molecular salt, C9H10N5 +·C7H7O3S−, the asymmetric unit consists of a 2,4-diamino-6-phenyl-1,3,5-triazin-1-ium cation and a 4-methylbenzenesulfonate anion. The cation is protonated at the N atom lying between the amine and phenyl substituents. The protonated N and amino-group N atoms are involved in hydrogen bonding with the sulfonate O atoms through a pair of intermolecular N—H...O hydrogen bonds, giving rise to a hydrogen-bonded cyclic motif with R 2 2(8) graph-set notation. The inversion-related molecules are further linked by four N—H...O intermolecular interactions to produce a complementary DDAA (D = donor, A = acceptor) hydrogen-bonded array, forming R 2 2(8), R 4 2(8) and R 2 2(8) ring motifs. The centrosymmetrically paired cations form R 2 2(8) ring motifs through base-pairing via N—H...N hydrogen bonds. In addition, another R 3 3(10) motif is formed between centrosymetrically paired cations and a sulfonate anion via N—H...O hydrogen bonds. The crystal structure also features weak S=O...π and π–π interactions. Hirshfeld surface and fingerprint plots were employed in order to further study the intermolecular interactions.


Author(s):  
Tristan Neumann ◽  
Inke Jess ◽  
Christian Näther

The asymmetric unit of the polymeric title compound, {[Cd(NCS)2(C6H6N2S)]·2CH3OH}n, consists of one cadmium(II) cation that is located on a centre of inversion as well as one thiocyanate anion, one pyridine-4-carbothioamide ligand and one methanol molecule in general positions. The CdIIcations are octahedrally coordinated by the pyridine N atom of two pyridine-4-carbothioamide ligands and by the S and N atoms of four thiocyanate anions and are linked into chains along [010] by pairs of anionic ligands. These chains are further linked into layers extending along (201) by intermolecular N—H...O and O—H...S hydrogen bonds. One of the amino H atoms of the pyridine-4-carbothioamide ligand is hydrogen-bonded to the O atom of a methanol molecule, and a symmetry-related methanol molecule is the donor group to the S atom of another pyridine-4-carbothioamide ligand whereby each of the pyridine-4-carbothioamide ligands forms two pairs of centrosymmetric N—H...S and O—H...S hydrogen bonds. The methanol molecules are equally disordered over two orientations.


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