Zinc(II) and nickel(II) complexes of 3,5-dimethyl-1-(pyridin-2-yl)-1H-pyrazole: relationship between fluorescence and crystal packing

Author(s):  
Magdalena Małecka ◽  
Joachim Kusz ◽  
Peter Mayer ◽  
Marta Sobiesiak ◽  
Elzbieta Budzisz

Two novel coordination complexes, namely, dichlorido[3,5-dimethyl-1-(pyridin-2-yl-κN)-1H-pyrazole-κN 2]zinc(II), [ZnCl2(C10H11N3)], 1, and aquachloridobis[3,5-dimethyl-1-(pyridin-2-yl-κN)-1H-pyrazole-κN 2]nickel(II) chloride monohydrate, [NiCl(C10H11N3)(H2O)]Cl·H2O, 2, have been synthesized. The crystal structure analyses revealed that complexes 1 and 2 are mononuclear and have ZnN2Cl2 distorted tetrahedral and NiN4OCl distorted octahedral structures, respectively. Complex 1 displays a dimer in the crystal structure, while complex 2 forms a chain along the [010] direction. The fluorescence properties of both complexes were also investigated. A search of the Cambridge Structural Database for other complexes of the ligand 3,5-dimethyl-1-(pyridin-2-yl)-1H-pyrazole (L) shows that there exist different coordination polyhedra with different arrangements as monomers, dimers and polycyclic structures. Here it has also been demonstrated that there is a relationship between the crystal packing and the fluorescence properties of ZnII and CdII complexes of L.

2014 ◽  
Vol 70 (9) ◽  
pp. m307-m308
Author(s):  
Hengye Zou ◽  
Yanjuan Qi

In the polymeric title compound, [Co(C2O4)(C14H14N4O2)]n, the CoIIatom is six-coordinated by two N atoms from symmetry-related bis[(pyridin-4-yl)methyl]oxalamide (BPMO) ligands and four O atoms from two centrosymmetric oxalate anions in a distorted octahedral coordination geometry. The CoIIatoms are linked by the oxalate anions into a chain running parallel to [100]. The chains are linked by the BPMO ligands into a three-dimensional architecture. In addition, N—H...O hydrogen bonds stabilize the crystal packing.


2002 ◽  
Vol 58 (3) ◽  
pp. 407-422 ◽  
Author(s):  
Frank H. Allen ◽  
W. D. Samuel Motherwell

The Cambridge Structural Database (CSD) and its associated software systems have formed the basis for more than 800 research applications in structural chemistry, crystallography and the life sciences. Relevant references, dating from the mid-1970s, and brief synopses of these papers are collected in a database, DBUse, which is freely available via the CCDC website. This database has been used to review research applications of the CSD in organic chemistry, including supramolecular applications, and in organic crystal chemistry. The review concentrates on applications that have been published since 1990 and covers a wide range of topics, including structure correlation, conformational analysis, hydrogen bonding and other intermolecular interactions, studies of crystal packing, extended structural motifs, crystal engineering and polymorphism, and crystal structure prediction. Applications of CSD information in studies of crystal structure precision, the determination of crystal structures from powder diffraction data, together with applications in chemical informatics, are also discussed.


2015 ◽  
Vol 71 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
Francisca N. Rein ◽  
Weizhong Chen ◽  
Brian L. Scott ◽  
Reginaldo C. Rocha

We report the structural characterization of [6′,6′′-bis(pyridin-2-yl)-2,2′:4′,4′′:2′′,2′′′-quaterpyridine](2,2′-bipyridine)chloridoruthenium(II) hexafluoridophosphate, [RuCl(C10H8N2)(C30H20N6)]PF6, which contains the bidentate ligand 2,2′-bipyridine (bpy) and the tridendate ligand 6′,6′′-bis(pyridin-2-yl)-2,2′:4′,4′′:2′′,2′′′-quaterpyridine (tpy–tpy). The [RuCl(bpy)(tpy–tpy)]+monocation has a distorted octahedral geometry at the central RuIIion due to the restricted bite angle [159.32 (16)°] of the tridendate ligand. The Ru-bound tpy and bpy moieties are nearly planar and essentially perpendicular to each other with a dihedral angle of 89.78 (11)° between the least-squares planes. The lengths of the two Ru—N bonds for bpy are 2.028 (4) and 2.075 (4) Å, with the shorter bond being opposite to Ru—Cl. For tpy–tpy, the mean Ru—N distance involving the outer N atomstransto each other is 2.053 (8) Å, whereas the length of the much shorter bond involving the central N atom is 1.936 (4) Å. The Ru—Cl distance is 2.3982 (16) Å. The free uncoordinated moiety of tpy–tpy adopts atrans,transconformation about the interannular C—C bonds, with adjacent pyridyl rings being only approximately coplanar. The crystal packing shows significant π–π stacking interactions based on tpy–tpy. The crystal structure reported here is the first for a tpy–tpy complex of ruthenium.


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.


Author(s):  
Ana Paula Lopes de Melo ◽  
Leandro Bresolin ◽  
Bianca Barreto Martins ◽  
Vanessa Carratu Gervini ◽  
Adriano Bof de Oliveira

The reaction in methanol of CuII acetate monohydrate with 5-fluoroisatin 3-oxime deprotonated with KOH in a 1:2 molar ratio and recrystallization from pyridine yielded the title compound, [Cu(C8H4FN2O2)2(C5H5N)2]. In the centrosymmetric complex, the anionic form of the isatin oxime acts as a κ2 N,O donor, building five-membered metallarings. The CuII cation is sixfold coordinated in a slightly distorted octahedral environment by two trans, equatorial, anionic isatin derivatives and two trans pyridine ligands in axial positions. The complexes are linked by hydrogen bonding into a three-dimensional network, which is also stabilized by π–π stacking interactions [centroid-to-centroid distance = 3.7352 (9) Å] and C—H...π contacts. The Hirshfeld surface analysis indicates that the major contributions for the crystal packing are H...H (31.80%), H...C (24.30%), H...O (15.20%) and H...F (10.80%). This work is the second report in the literature of a crystal structure of a coordination compound with isatin 3-oxime ligands (coordination chemistry).


2014 ◽  
Vol 70 (a1) ◽  
pp. C1018-C1018
Author(s):  
Mark Oliveira ◽  
Peter Wood ◽  
Magali Hickey ◽  
Orn Almarsson ◽  
Juan Alvarez ◽  
...  

Crystalline organic hydrates in the Cambridge Structural Database have been surveyed to better understand water coordination environments and hydration likelihood. Particular emphasis has been paid to the subsets of bioactive organic hydrates and five classes of compound that are important in terms of pharmaceutical activity. Bioactive compounds are found to exhibit a greater hydration likelihood than general small organic compounds, but the distribution of environments remains the same, with the most common by far being where water accepts once and donates twice (DDA, 49.8%).


2015 ◽  
Vol 71 (10) ◽  
pp. 921-928 ◽  
Author(s):  
Kulsoom Kamal ◽  
Hardesh K. Maurya ◽  
Atul Gupta ◽  
Prema G. Vasudev

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.


Author(s):  
Tatyana V. Kudayarova ◽  
Elena A. Danilova ◽  
Yuliya A. Piteva ◽  
Kristina E. Mochalina ◽  
Maxim V. Dmitriev

This paper discusses the synthesis and structure of a complex compound based on 3,5-diamino-1H-1,2,4-triazole (guanazole) with gallium ions, formed by the interaction of anhydrous gallium (III) chloride and guanazole in dried methanol. After distilling off the solvent under vacuum, the resulting product was washed with hexane, acetone. The target compound was extracted with acetonitrile, and slow evaporation of the latter at room temperature for three days resulted in beige-colored crystals, which were characterized by IR spectroscopy, elemental analysis, mass-spectrometry and X-ray diffraction analysis. The complex composition of gallate, C2H6N5+∙[GaCl4], exists as two crystallographically independent cations and two anions. The complex compound crystallizes in the centrosymmetric space group of the monoclinic syngony. The tetrachlorogallate anion is a slightly distorted tetrahedron, which is typical of structures of this type. 1,2,4-triazolium cations are selectively protonated on the N4 and N4A atoms, however, the site of the preferential localization of the positive charge is the N2 and N2A atoms. In addition to the electrostatic interaction of oppositely charged ions, a developed system of hydrogen bonds plays an important role in the stabilization of the crystal packing: almost all hydrogen and chlorine atoms are involved in its formation. Each of the crystallographically independent cations forms a centrosymmetric dimer due to the intermolecular hydrogen bond N2 – H2···N3 and N2A – H2A···N3A.  A full set of X-ray data is deposited into the Cambridge Structural Database of Compounds - the Cambridge Structural Database (Contributor CCDC 1894815) and it can be gotten from the site www.ccdc.cam.ac.uk/data_request/cif.


2016 ◽  
Vol 72 (11) ◽  
pp. 1549-1553 ◽  
Author(s):  
Sourav J. Bharali ◽  
Sanchay J. Bora ◽  
Birinchi K. Das

The title compound, [Mn2(C7H4NO4)4(C6H7N)4] or [Mn2(μ-NBz)2(κ2-NBz)2(4-Mepy)4], where NBz is 4-nitrobenzoate and 4-Mepy is 4-methylpyridine, is a centrosymmetric dinuclear complex in which the MnIIatoms are bridged by two NBz ligands with Mn...Mn = 4.1324 (4) Å. The MnIIatom in this dimeric species is present in a distorted octahedral environment with the four coordinating O atoms forming the equatorial plane and the two pyridyl N atoms occupying the axial sites. An important structural feature of the dimeric complex is that each of the bridging carboxylate ligands binds to the metal ions in an asymmetric fashion involving bent and linear Mn—O—C units. The crystal packing is consolidated by C—H...O and C—H...π interactions.


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