Influence of ring size on the strength of carbon bonding complexes between anions and perfluorocycloalkanes

2014 ◽  
Vol 16 (36) ◽  
pp. 19192-19197 ◽  
Author(s):  
Antonio Bauzá ◽  
Tiddo J. Mooibroek ◽  
Antonio Frontera
Keyword(s):  
Ab Initio ◽  
Cambridge Structural Database ◽  
Ring Size ◽  
Database Analysis ◽  
Structural Database ◽  
High Level ◽  
Carbon Bonding

High level ab initio calculations and Cambridge Structural Database analysis were used to demonstrate the importance of carbon bonding in cyclobutane rings.

Crystal structures of four δ-keto esters and a Cambridge Structural Database analysis of cyano–halogen interactions

2015 ◽  
Vol 71 (10) ◽  
pp. 921-928 ◽  
Author(s):  
Kulsoom Kamal ◽  
Hardesh K. Maurya ◽  
Atul Gupta ◽  
Prema G. Vasudev
Keyword(s):  
Crystal Structures ◽  
Crystal Packing ◽  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Cambridge Structural Database ◽  
Database Analysis ◽  
Molecular Conformations ◽  
Keto Esters ◽  
Organic Molecular Crystals ◽  
Structural Database

The revived interest in halogen bonding as a tool in pharmaceutical cocrystals and drug design has indicated that cyano–halogen interactions could play an important role. The crystal structures of four closely related δ-keto esters, which differ only in the substitution at a single C atom (by H, OMe, Cl and Br), are compared, namely ethyl 2-cyano-5-oxo-5-phenyl-3-(piperidin-1-yl)pent-2-enoate, C19H22N2O3, (1), ethyl 2-cyano-5-(4-methoxyphenyl)-5-oxo-3-(piperidin-1-yl)pent-2-enoate, C20H24N2O4, (2), ethyl 5-(4-chlorophenyl)-2-cyano-5-oxo-3-(piperidin-1-yl)pent-2-enoate, C19H21ClN2O3, (3), and the previously published ethyl 5-(4-bromophenyl)-2-cyano-5-oxo-3-(piperidin-1-yl)pent-2-enoate, C19H21BrN2O3, (4) [Maurya, Vasudev & Gupta (2013).RSC Adv.3, 12955–12962]. The molecular conformations are very similar, while there are differences in the molecular assemblies. Intermolecular C—H...O hydrogen bonds are found to be the primary interactions in the crystal packing and are present in all four structures. The halogenated derivatives have additional aromatic–aromatic interactions and cyano–halogen interactions, further stabilizing the molecular packing. A database analysis of cyano–halogen interactions using the Cambridge Structural Database [CSD; Groom & Allen (2014).Angew. Chem. Int. Ed.53, 662–671] revealed that about 13% of the organic molecular crystals containing both cyano and halogen groups have cyano–halogen interactions in their packing. Three geometric parameters for the C—X...N[triple-bond]C interaction (X = F, Cl, Br or I),viz.the N...Xdistance and the C—X...N and C—N...Xangles, were analysed. The results indicate that all the short cyano–halogen contacts in the CSD can be classified as halogen bonds, which are directional noncovalent interactions.

Insights into the C–H⋯F–C hydrogen bond by Cambridge Structural Database analyses and computational studies

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26932-26940 ◽  
Author(s):  
Sagarika Dev ◽  
Sudeep Maheshwari ◽  
Angshuman Roy Choudhury
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Ab Initio ◽  
Gas Phase ◽  
Cambridge Structural Database ◽  
Computational Studies ◽  
Structural Database

C–H⋯F–C hydrogen bonding is analysed among fluorinated ethenes using ab initio calculations in the gas phase to understand the nature, strength and directionality of these interactions.

Hydrogen bonding at C=Se acceptors in selenoureas, selenoamides and selones

2016 ◽  
Vol 72 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Dikima Bibelayi ◽  
Albert S. Lundemba ◽  
Frank H. Allen ◽  
Peter T. A. Galek ◽  
Juliette Pradon ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Ab Initio ◽  
Crystal Engineering ◽  
Cambridge Structural Database ◽  
Bond Lengths ◽  
Partial Charges ◽  
Structural Database

In recent years there has been considerable interest in chalcogen and hydrogen bonding involving Se atoms, but a general understanding of their nature and behaviour has yet to emerge. In the present work, the hydrogen-bonding ability and nature of Se atoms in selenourea derivatives, selenoamides and selones has been explored using analysis of the Cambridge Structural Database andab initiocalculations. In the CSD there are 70 C=Se structures forming hydrogen bonds, all of them selenourea derivatives or selenoamides. Analysis of intramolecular geometries andab initiopartial charges show that this bonding stems from resonance-induced Cδ+=Seδ−dipoles, much like hydrogen bonding to C=S acceptors. C=Se acceptors are in many respects similar to C=S acceptors, with similar vdW-normalized hydrogen-bond lengths and calculated interaction strengths. The similarity between the C=S and C=Se acceptors for hydrogen bonding should inform and guide the use of C=Se in crystal engineering.

scholarly journals Geometrical and energetic characteristics of Se…Se interactions in crystal structures of organoselenium molecules

CrystEngComm ◽  
2021 ◽  
Author(s):  
Ivana S Veljković ◽  
Danijela S. Kretić ◽  
Dušan Ž Veljković
Keyword(s):  
Crystal Structures ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Cambridge Structural Database ◽  
Structural Database ◽  
High Level

Non-covalent selenium-selenium interactions between selenium-containing organic molecules were studied in crystal structures from the Cambridge Structural Database and by high-level quantum chemical calculations. Se…Se contacts in crystal structures were analyzed...

“Like–like” tetrel bonding interactions between Sn centres: a combinedab initioand CSD study

2019 ◽  
Vol 48 (30) ◽  
pp. 11208-11216 ◽  
Author(s):  
Antonio Franconetti ◽  
Antonio Frontera
Keyword(s):  
Ab Initio ◽  
Cambridge Structural Database ◽  
Structural Database

In this manuscript, we combine a search in the Cambridge Structural Database (CSD) andab initiocalculations (RI-MP2/def2-TZVP level of theory) to analyse the ability of Sn to establish ‘like–like’ tetrel bonding interactions.

Non-aromatic endocyclic angle at the ring fusion with the aromatic ring in benzocyclopentene and -hexene, revisited

2004 ◽  
Vol 60 (3) ◽  
pp. 293-299
Author(s):  
Dirk J. A. De Ridder ◽  
Hans-Beat Bürgi
Keyword(s):  
Bond Length ◽  
Aromatic Ring ◽  
Cambridge Structural Database ◽  
Mirror Plane ◽  
Ring Size ◽  
Acta Cryst ◽  
Ring Fusion ◽  
X Ray ◽  
Fused Ring ◽  
Structural Database

X-ray geometries of monocycloalkenobenzenes with a fused-ring size of r = 5, 6 were obtained by the use of the Cambridge Structural Database. In contrast to Allen's study [Acta Cryst. (1981), B37, 900–906], the data were not averaged over exact or imposed m ad symmetry (m ad is the mirror plane going through the midpoint of the aromatic ring fusion bond and the aromatic bond parallel to it). The distribution of the non-aromatic endocyclic angle ∊ at the ring fusion clearly shows two and three, respectively, distinct curves for r = 5 and r = 6. The respective ranges are 104.3–112.6 and 104.4–123.2°. If one of the C atoms directly attached to the aromatic ring is sp 2 hybridized, the bond length e between the aromatic ring and this atom is shortened by some 0.044 (15) and 0.027 (12) Å for r = 5 and r = 6, respectively. However, for r = 5, e is only shortened by 0.030 (17) Å when both C atoms directly attached to the aromatic ring are sp 2 hybridized. For r = 5, the endocyclic angle ∊ is 1.2 (13)° smaller at the side involving the sp 2 hybridized C atom.

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