scholarly journals π-Stacking Stopper-Macrocycle Stabilized Dynamically Interlocked [2]Rotaxanes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4704
Author(s):  
Sing-Ming Chan ◽  
Fung-Kit Tang ◽  
Ching-Yau Lam ◽  
Chak-Shing Kwan ◽  
Sam C. K. Hau ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Thermodynamic Stability ◽  
Combinatorial Library ◽  
Aromatic Rings ◽  
Interlocked Molecules ◽  
X Ray ◽  
Π Stacking ◽  
Dynamic Combinatorial Library

The synthesis of mechanically interlocked molecules is valuable due to their unique topologies. With π-stacking intercomponent interaction, e.g., phenanthroline and anthracene, novel [2]rotaxanes have been synthesized by dynamic imine clipping reaction. Their X-ray crystal structures indicate the π-stackings between the anthracene moiety (stopper) on the thread and the (hetero)aromatic rings at the macrocycle of the rotaxanes. Moreover, the length of glycol chains affects the extra π-stacking intercomponent interactions between the phenyl groups and the dimethoxy phenyl groups on the thread. Dynamic combinatorial library has shown at best 84% distribution of anthracene-threaded phenanthroline-based rotaxane, coinciding with the crystallography in that the additional π-stacking intercomponent interactions could increase the thermodynamic stability and selectivity of the rotaxanes.

Intermolecular interactions and electronic properties in phosphino-(oligothiophene) palladium(II) and platinum(II) complexes

2007 ◽  
Vol 85 (5) ◽  
pp. 383-391 ◽  
Author(s):  
Tracey L Stott ◽  
Michael O Wolf ◽  
Brian O Patrick
Keyword(s):  
Solid State ◽  
Metal Complexes ◽  
Electronic Properties ◽  
Crystal Structures ◽  
Structural Properties ◽  
Absorption Spectra ◽  
Intermolecular Interactions ◽  
Electronic Spectra ◽  
X Ray ◽  
Π Stacking

A series of Pt(II) and Pd(II) complexes containing diphenylphosphino-substituted oligothiophene ligands ranging from 1 to 3 thiophene rings in length have been prepared. Crystal structures of four of these complexes were determined via single X-ray crystal diffraction and the solid-state packing arrangements found to vary with both the metal and the thiophene-containing ligand. In some cases, π-stacking between thiophene rings are found for the oligothiophene ligands. Solution and solid-state absorption spectra of these complexes are reported.Key words: oligothiophenes, metal complexes, structural properties, electronic spectra.

Detection of Ligands from a Dynamic Combinatorial Library by X-ray Crystallography

2003 ◽  
Vol 42 (37) ◽  
pp. 4479-4482 ◽  
Author(s):  
Miles S. Congreve ◽  
Deborah J. Davis ◽  
Lindsay Devine ◽  
Cesare Granata ◽  
Marc O′Reilly ◽  
...  
Keyword(s):  
Combinatorial Library ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dynamic Combinatorial Library

Polysulfonylamine, CLXIX. Intermolekulare Wechselwirkungen in kristallinen Di(organosulfonyl)aminen. Teil 1. Di(4-brombenzolsulfonyl)amin: Zwei Konformationspolymorphe und Strukturverwandtschaft eines Polymorphs mit dem entsprechenden 2,4-Dimethylpyridinium-Salz / Polysulfonylamines, CLXIX. Intermolecular Interactions in Crystalline Di(organosulfonyl)- amines. Part 1. Di(4-bromobenzenesulfonyl)amine: Two Conformational Polymorphs and the Structural Relationship of one Polymorph to the Corresponding 2,4-Dimethylpyridinium Salt

2004 ◽  
Vol 59 (6) ◽  
pp. 661-672 ◽  
Author(s):  
Virginia Lozano ◽  
Oliver Moers ◽  
Peter G. Jones ◽  
Armand Blaschette
Keyword(s):  
Hydrogen Bonds ◽  
Mirror Symmetry ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Π Stacking ◽  
Dimensional Network ◽  
Weak Hydrogen Bonds ◽  
Relationship Of

Two crystal structures (polymorphs) of di(4-bromobenzenesulfonyl)amine (1), as determined by low-temperature single-crystal X-ray diffraction, are reported: Form A, monoclinic, P21/c, Z' = 1; form B: monoclinic, P21/c, Z' = 2. In A, the molecule adopts an extended conformation approximating to C2 symmetry, whereas the two independent molecules of form B display a folded hair-pin conformation with pseudo-mirror symmetry [torsion τ (C-S···S’-C’) and intercentroid distance dIC of the aromatic rings in A: 173.2° and 750.8 pm, in B: −5.4/−8.90° and 364.1/366.5 pm]. The packings of both polymorphs consist of layers, in which the molecules are connected by N-H···O hydrogen bonds in one and by Br···O interactions in the other dimension. The 1:1 onium salt (2; monoclinic, P21/n, Z' = 1) produced on N-deprotonation of 1 with 2,4-dimethylpyridine is structurally related to B. Its packing involves strands of formula units, whereby the anions retain the folded conformation (τ = 5.8°, dIC = 372.5 pm) and perfectly mimic the catemeric Br···O pattern of B, while the cations are isotactically connected to the anion backbone via an N-H(···O)2 three-centre bond. In all structures, a three-dimensional network of weak hydrogen bonds C-H···A (A = O, in 2 also N−) and C-H···Br contacts supports the controlling N-H···O and Br···O interactions; moreover, an intermolecular (π···π) stacking dimer of the type phenyl/phenyl and a (π···π) stacking trimer of the type phenyl/pyridinium/phenyl have been identified in A and 2, respectively. None of the structures exhibits very short bromine-bromine contacts suggestive of specific attractive forces.

scholarly journals Recurrent π–π stacking motifs in three new 4,5-dihydropyrazolyl–thiazole–coumarin hybrids: X-ray characterization, Hirshfeld surface analysis and DFT calculations

2020 ◽  
Vol 44 (34) ◽  
pp. 14592-14603 ◽  
Author(s):  
Murtaza Madni ◽  
Muhammad Naeem Ahmed ◽  
Muhammad Hafeez ◽  
Muhammad Ashfaq ◽  
Muhammad Nawaz Tahir ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Crystal Structures ◽  
Surface Analysis ◽  
Hirshfeld Surface ◽  
Hirshfeld Surface Analysis ◽  
X Ray ◽  
Π Stacking

Two different π–π stacking modes are described, studied and characterized in the crystal structures of 4,5-dihydropyrazolyl–thiazole–coumarin hybrids, including a partial aliphatic ring.

A new method of syntheses of 18-membered macrocyclic diphenyltin(IV) compounds and crystal structures of {Ph2Sn[S(C6H3NO)O]}3·Y (Y = 2H2O or 4C6H6) and {Ph3Sn[S(C6H3NO)O]SnPh3(EtOH)}·[EtOH]

2004 ◽  
Vol 82 (5) ◽  
pp. 608-615 ◽  
Author(s):  
Chunlin Ma ◽  
Qin Jiang ◽  
Rufen Zhang
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
New Method ◽  
Macrocyclic Compounds ◽  
X Ray ◽  
Stacking Interaction ◽  
Π Stacking ◽  
Triphenyltin Chloride ◽  
Π Stacking Interaction ◽  
Solvent Molecules

Two diphenyltin(IV) compounds: {Ph2Sn[S(C6H3NO)O]}3·Y (Y = 2H2O, 1; 4C6H6, 2) have been unexpectedly obtained by the reactions of triphenyltin chloride with 2-mercaptonicotinic acid in the presence of Et3N. However, by the reaction of the same reactants in the presence of EtONa, only a new triphenyltin(IV) compound ({Ph3Sn[S(C6H3NO)O]SnPh3(EtOH)}·[EtOH], 3) was obtained. The X-ray analyses reveal that compounds 1 and 2 are trinuclear, 18-membered macrocyclic compounds while 3 is a dinuclear compound. Specially, π-π stacking interaction was recognized in crystals of compound 1, which makes it a dimer. Co-crystallization was found in the crystals of all the three compounds 1, 2, and 3, the co-crystallized solvent molecules are water, benzene, and ethanol molecules, respectively. A possible dephenylation mechanism of 1 and 2 was illustrated in detail.Key words: triphenyltin, 2-mercaptonicotinic acid, dephenylation, macrocyclic, π-π stacking interaction, co-crystallization, crystal structure.

2,2'-Bipyridine Mercury(II) Complexes [Hg(bpy)(NO2)X] (X = NO2 –, SCN– , CH3COO–); Π-Π Stacking In The Crystal Structure Of [Hg(bpy)(NO2)2]

2005 ◽  
Vol 60 (3) ◽  
pp. 289-293 ◽  
Author(s):  
Ali Ramazani ◽  
Ali Morsali ◽  
Leila Dolatyari ◽  
Bijan Ganjeie
Keyword(s):  
Crystal Structure ◽  
Nmr Spectroscopy ◽  
Aromatic Rings ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Π Stacking ◽  
Π Stacking Interaction ◽  
Coordinate Geometry ◽  
C Nmr

The mercury(II) complexes of 2,2′-bipyridine (bpy), [Hg(bpy)(NO2)2], [Hg(bpy)(NO2) (CH3COO)], and [Hg(bpy)(NO2)(NCS)] have been synthesized and characterized by elemental analysis, IR, 1H NMR and 13C NMR spectroscopy. The structure of [Hg(bpy)(NO2)2] has been confirmed by X-ray crystallography. The complex is a monomer and the Hg atom has an unsymmetrical six-coordinate geometry, formed by two nitrogen atoms of the bpy ligand and four oxygen atoms of the two nitrite anions. There is a short intermolecular π-π stacking interaction between parallel aromatic rings

Effect of chain ends on the structure of aramid oligomers

2008 ◽  
Vol 86 (1) ◽  
pp. 7-19 ◽  
Author(s):  
Hakim Mehenni ◽  
Hélène Guillou ◽  
Christian Tessier ◽  
Josée Brisson
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Model Compound ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Internal Distribution ◽  
Diffraction Patterns ◽  
Additional Form

Synthesis, X-ray diffraction, and Fourier transform infrared spectroscopy of aliphatic–aromatic aramid oligomers are reported with the aim of shedding light on the effect of end-chain substituent on the morphology and structure of poly(para-phenylene terephthalamide) or PPTA. Three types of X-ray powder diffraction patterns were observed: one similar to that of PPTA form I, one similar to that of PPTA form II, and an additional form never reported. Some compounds, differing by their internal distribution of amide–aromatic rings, adopt two different crystal structures, whereas compounds having the same internal amide–aromatic arrangements, but differing by the nature of the end-groups, can adopt the same crystal structure. This clearly shows that both factors influence the packing adopted by the chains. Single-crystal structures of two polymorphs of a nitro-terminated model compound were resolved; both forms incorporate dimethyl formamide, and both show completely different packing. Infrared amide I and II band positions of most studied compounds match those observed for PPTA forms I or II, indicating that they exhibit planar hydrogen bonded sheets of molecules.Key words: aramid, crystal structure, poly(para-phenylene terephtalamide).

STERIC INHIBITION OF RESONANCE: I. 9-NITROANTHRACENE AND 9,10-DINITROANTHRACENE

1959 ◽  
Vol 37 (2) ◽  
pp. 351-357 ◽  
Author(s):  
James Trotter
Keyword(s):  
Crystal Structures ◽  
Nitro Derivative ◽  
Resonance Interaction ◽  
Vibration Frequencies ◽  
Characteristic Vibration ◽  
Aromatic Rings ◽  
X Ray ◽  
Steric Inhibition Of Resonance

Detailed X-ray analyses of the crystal structures of 9-nitroanthracene and 9,10-dinitro-anthracene have shown that the nitro groups are tilted out of the planes of the aromatic rings by 84.7° in the nitro derivative and 63.7° in the dinitro. The decreases in resonance interaction resulting from these deviations from coplanarity have been correlated with the characteristic vibration frequencies of the nitro groups.

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