Hydrogen-bond coordination in organic crystal structures: statistics, predictions and applications

Author(s):  
Peter T. A. Galek ◽  
James A. Chisholm ◽  
Elna Pidcock ◽  
Peter A. Wood

Statistical models to predict the number of hydrogen bonds that might be formed by any donor or acceptor atom in a crystal structure have been derived using organic structures in the Cambridge Structural Database. This hydrogen-bond coordination behaviour has been uniquely defined for more than 70 unique atom types, and has led to the development of a methodology to construct hypothetical hydrogen-bond arrangements. Comparing the constructed hydrogen-bond arrangements with known crystal structures shows promise in the assessment of structural stability, and some initial examples of industrially relevant polymorphs, co-crystals and hydrates are described.

CrystEngComm ◽  
2021 ◽  
Author(s):  
Leen N. Kalash ◽  
Jason C. Cole ◽  
Royston C. B. Copley ◽  
Colin M. Edge ◽  
Alexandru A. Moldovan ◽  
...  

Analysis of the molecular and structural features of the GSK crystal structure database and Cambridge Structural Database leads to improved reliability in hydrogen bond propensity models for pharmaceutical polymorphs.


2009 ◽  
Vol 65 (1) ◽  
pp. 68-85 ◽  
Author(s):  
Peter T. A. Galek ◽  
László Fábián ◽  
Frank H. Allen

The significance of hydrogen bonding and its variability in polymorphic crystal structures is explored using new automated structural analysis methods. The concept of a chemically equivalent hydrogen bond is defined, which may be identified in pairs of structures, revealing those types of bonds that may persist, or not, in moving from one polymorphic form to another. Their frequency and nature are investigated in 882 polymorphic structures from the Cambridge Structural Database. A new method to compare conformations of equivalent molecules is introduced and applied to derive distinct subsets of conformational and packing polymorphs. The roles of chemical functionality and hydrogen-bond geometry in persistent interactions are systematically explored. Detailed structural comparisons reveal a large majority of persistent hydrogen bonds that are energetically crucial to structural stability.


Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.


Author(s):  
Maciej Bujak

The molar ratio variations of organic and inorganic reactants of chloridobismuthates(III) with N,N-dimethylethane-1,2-diammonium, [(CH3)2NH(CH2)2NH3]2+, and N,N,N′,N′-tetramethylguanidinium, [NH2C{N(CH3)2}2]+, cations lead to the formation of four different products, namely, tris(N,N-dimethylethane-1,2-diammonium) bis[hexachloridobismuthate(III)], [(CH3)2NH(CH2)2NH3]3[BiCl6]2 (1), catena-poly[N,N-dimethylethane-1,2-diammonium [[tetrachloridobismuthate(III)]-μ-chlorido]], {[(CH3)2NH(CH2)2NH3][BiCl5]} n (2), tris(N,N,N′,N′-tetramethylguanidinium) tri-μ-chlorido-bis[trichloridobismuthate(III)], [NH2C{N(CH3)2}2]3[Bi2Cl9] (3), and catena-poly[N,N,N′,N′-tetramethylguanidinium [[dichloridobismuthate(III)]-di-μ-chlorido]], {[NH2C{N(CH3)2}2][BiCl4]} n (4). The hybrid crystals 1–4, containing relatively large but different organic cations, are composed of four distinct anionic substructures. They are built up from isolated [BiCl6]3− octahedra in 1, from face-sharing bioctahedral [Bi2Cl9]3− units in 3, from polymeric corner-sharing {[BiCl5]2−} n chains in 2 and from edge-sharing {[BiCl4]−} n chains in 4. The distortions shown by the single [BiCl6]3− polyhedra in 1–4 are associated with intrinsic interactions within the anionic substructures and the organic...inorganic substructures interactions, namely, N/C—H...Cl hydrogen bonds. The first factor is the stronger, which is evident in comparison of the experimentally determined geometrical and calculated distortion parameters for the isolated octahedron in 1 to the more complex inorganic substructures in 2–4. The formation of N—H...Cl hydrogen bonds, in terms of their number and strength, is favoured for 1 and 3 containing relatively easily accessed hydrogen-bond acceptors of isolated [BiCl6]3− and [Bi2Cl9]3− units. The studies of the deviations from regularity of the [BiCl6]3− octahedra within inorganic substructures were supported by a survey of the Cambridge Structural Database, which confirmed the role played by different factors in the variations in geometry of the inorganic anions.


2005 ◽  
Vol 38 (4) ◽  
pp. 694-696 ◽  
Author(s):  
Jacco van de Streek ◽  
Sam Motherwell

In order to establish the effect of exchanging one functional group by another on the crystal structure, one would like to be able to search the Cambridge Structural Database for all pairs of crystal structures where this substitution has been made. A program calledGRX(group exchange) was written for that purpose.


CrystEngComm ◽  
2014 ◽  
Vol 16 (14) ◽  
pp. 3040-3046 ◽  
Author(s):  
Xiao-Peng Xuan ◽  
Liang-Liang Chang ◽  
Heng Zhang ◽  
Na Wang ◽  
Yang Zhao

Hydrogen bonds such as the classic O–H⋯X (halide ion) hydrogen bond and the carboxyl group dimer were observed in the crystal structures of hydrophilic and hydrophobic COOH-functionalized imidazolium ionic liquids, respectively.


2002 ◽  
Vol 58 (3) ◽  
pp. 380-388 ◽  
Author(s):  
Frank H. Allen

The Cambridge Structural Database (CSD) now contains data for more than a quarter of a million small-molecule crystal structures. The information content of the CSD, together with methods for data acquisition, processing and validation, are summarized, with particular emphasis on the chemical information added by CSD editors. Nearly 80% of new structural data arrives electronically, mostly in CIF format, and the CCDC acts as the official crystal structure data depository for 51 major journals. The CCDC now maintains both a CIF archive (more than 73000 CIFs dating from 1996), as well as the distributed binary CSD archive; the availability of data in both archives is discussed. A statistical survey of the CSD is also presented and projections concerning future accession rates indicate that the CSD will contain at least 500000 crystal structures by the year 2010.


2006 ◽  
Vol 62 (4) ◽  
pp. 567-579 ◽  
Author(s):  
Jacco van de Streek

A computer program has been written that removes suspicious crystal structures from the Cambridge Structural Database and clusters the remaining crystal structures as polymorphs or redeterminations. For every set of redeterminations, one crystal structure is selected to be the best representative of that polymorph. The results, 243 355 well determined crystal structures grouped by unique polymorph, are presented and analysed.


2012 ◽  
Vol 68 (4) ◽  
pp. o164-o169 ◽  
Author(s):  
Mehrdad Pourayoubi ◽  
Atekeh Tarahhomi ◽  
Fatemeh Karimi Ahmadabad ◽  
Karla Fejfarová ◽  
Arie van der Lee ◽  
...  

InN,N′-di-tert-butyl-N′′,N′′-dimethylphosphoric triamide, C10H26N3OP, (I), andN,N′,N′′,N′′′-tetra-tert-butoxybis(phosphonic diamide), C16H40N4O3P2, (II), the extended structures are mediated by P(O)...(H—N)2interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)2hydrogen bonds, givingR21(6) loops and forming two independent chains parallel to theaaxis. Of the 12 independenttert-butyl groups, five are disordered over two different positions with occupancies ranging from 1 \over 6 to 5 \over 6. In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)2hydrogen bonds giveS(6) andR22(8) rings, and the molecules form extended chains parallel to thecaxis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)2and (NH)2P(O)(O)P(O)(NH)2skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen-bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]x(x= 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)2P(O)(NH) and P(O)(NH)3fragments.


Author(s):  
Jason C. Cole ◽  
Colin R. Groom ◽  
Murray G. Read ◽  
Ilenia Giangreco ◽  
Patrick McCabe ◽  
...  

This analysis attempts to answer the question of whether similar molecules crystallize in a similar manner. An analysis of structures in the Cambridge Structural Database shows that the answer is yes – sometimes they do, particularly for single-component structures. However, one does need to define what we mean bysimilarin both cases. Building on this observation we then demonstrate how this correlation between shape similarity and packing similarity can be used to generate potential lattices for molecules with no known crystal structure. Simple intermolecular interaction potentials can be used to minimize these potential lattices. Finally we discuss the many limitations of this approach.


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