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Propedeutyka kierunkowych oddziaływań miedzycząsteczkowych. Wiązania wodorowe, oddziaływania asocjacji warstwowej i wiązania halogenowe

Kruszyński R.

Zeszyty Naukowe. Chemia / Politechnika Łódzka

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2011

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Z. 50

5-47

EN

The review presents the typical bonding intermolecular interactions: hydrogen bonds, halogen bonds and stacking interactions. The first part describes the specific types of intermolecular interactions, including their definitions, energy and selected properties. The second part deals with the application of quantum-mechanical methods to study of intermolecular interactions, especially the appliance of the natural bond orbitals method, and usage of ab intio calculations for solving of structural problems appearing during the above mentioned studies. All above referred interactions have been presented in orbital terms. The third part describes the novel employment of graph theory to characterise the motifs formed by intermolecular interactions in the solid state.

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Structural Studies of Position 2 Modified Endomorphin-2 Analogs by NMR Spectroscopy and Molecular Modeling

Janecka A., Perlikowska R., Gach K., Fichna J., Mazur A., Kruszyński R., Janecki T., Jankowski S.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 7

1293-1307

EN

Endomorphin-2 (EM-2, Tyr-Pro-Phe-Phe-NH2) is an endogenous ligand for the mi-opioid receptor. To examine the importance of Pro2 in EM-2 structure, we synthesized a series of analogs in corporating piperidine-2-, 3- and 4-carboxylic acids (Pip, Nip and Inp, respectively) in position 2. Pip, Nip and Inp are six-membered mimics of Pro and can be considered as alfa-, beta- and gamma-amino acids, respectively. Receptor binding studies revealed that [(R)-Nip2]EM-2 had greatly in creased mi-opioid receptor affinity compared with the parent peptide, while two other analogs were in active. In order to determine which structural elements of [(R)-Nip2]EM-2 could be responsible for the out standing affinity of this analog, the solution conformations of EM-2 analogs in corporating Promimics were investigated by the combination of 2D 1H NMR measurements and molecular modeling calculations. Evaluating the ratios of cis/trans rotamers, aromatic inter actions and dihedral angles we have found that all three analogs exist as a mixture of cis/trans rotamers of the Tyr–Xaa peptide bond and have flexible, extended conformations, with no intramolecular hydrogen bonds or aromatic ring inter actions observed for EM-2. The obtained results do not allow to draw conclusions on the bioactive conformation of the most active analog. We can suggest that a well known preference of the substituents to occupy equatorial positions in six-membered rings, to gether with a greater distance between Tyr1 and Phe3 aromatic rings, in Nip, which is a beta-amino acid, as compared with EM-2, are the main differentiating factors which are responsible for the exceptional affinity of [(R)-Nip2]EM-2.

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Investigation of Tetrahalogenoferrates(III) with Cations of Nitrogen-Containing Organic Bases. X-ray Crystal Structure of 2,6-Dimethylpyridinium Tetrabromoferrate(III)

Wyrzykowski D., Kruszyński R., Styczeń E., Chmurzyński L.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 8

1503--1511

EN

The crystal and molecular structure of a new 2,6-dimethylpyridinium tetra bromo -ferrate(III), [2,6-LutH][FeBr4] was determined. The iron(III) cation adopts a slightly distorted tetrahedral coordination with one angle smaller than tetrahedral, three almost equal to the tetrahedral ones and two larger. The bond valences were computed. The total valence of the iron atom is equal to 3.24. In the structure N(1)–H(1)×××Br(3) hydrogen bond can be found.

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Crystal Structure and Magnetic Properties of Copper(II) Macrocyclic Compounds

Bieńko A., Mroziński J., Korybut-Daszkiewicz B, Kruszyński R.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 7

1383-1383

EN

The two higly unsaturated copper(II) macrocyclic complexes [CuL1](ClO4)2 (1) (L1 = N-dl-5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) and [CuL2](ClO4)2 (2) (L2 = N-dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) were synthesized and the crystal structures of both compounds were determined at 173(2) K. Complex 1 crystallizes monoclinic, space group P21/c, with a = 9.0929(5) Capital A, ring, b = 13.4683(5) Capital A, ring , c = 8.2886(4) ,Capital A, ring beta = 109.469(6)°, Z = 2, whereas 2 crystallizes at the same space group with a = 10.4891(2) Capital A, ring, b = 16.9924(4) Capital A, ring , c = 13.8780(3) Capital A, ring , beta = 105.150(2)° and Z = 4. Their magnetic measurements have been carried out over the temperature range 1.8–300 K using a Quantum Design SQUID magnetometer (MPMSXL - 5 type). The results indicate that both compounds be have as weakly interacting copper centers in the crystal lattice.

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The Synthesis, Spectroscopic Investigation,Crystal and Molecular Structure of the [ReCl2(N2COPh)(2,3'-bpy)(PPh3)2] Complex

Michalik S., Dzięgielewski J., Kruszyński R.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 5

685-691

EN

The [ReCl2(N2COPh)(2,3'-bpy)(PPh3)2] complex has been obtained in the reaction of [ReCl2(2-N2COPh-N',O)(PPh3)2] with an excess of 2,3'-bipyridyl. The [ReCl2(N2COPh)(2,3'-bpy)(PPh3)2] complex crystallizes in the triclinic space group P-1. The complex was characterized by IR, UV-VIS, and magnetical measurements. The geometries of the complex was optimized with the DFT method.

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The Bonds Analysis of Hexamethylenetetramine

Trzęsowska A., Kruszyński R.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 7

1155-1168

EN

Natural Bond Orbital (NBO) method was used for the investigation of the hexamethylenetetramine (hmt). The nature of bonds and electronic properties of the titled compound were analysed by means of quantum mechanical calculations on the structural molecular geometries from neutron diffraction measurements carried out in seven, different temperatures. Calculations were performed using density functional theory method (B3LYP) with 6-31++G(d,p) basis set. The values of total and stabilization energy, orbital populations, vibrational frequencies, dipole moments are discussed. As expected, the total hmt energy value decreases as the temperature decreases. The most profitable energy value was obtained for the lowest hmt measurement temperature, which implies that the significant and favourable reduction of thermal motion took place. The geometric parameters of hmt molecule are similar in all structures, the only normality is the shortening and hence enhancing of C-N bond with the temperature increasing. The NBO analysis of donor-acceptor interactions resulted in decreasing of localized nN, sigma CH orbital occupancy, increasing of CN * occupancy and stabilization energy associated with following delocalizations: nN sigma CN * and sigma CH sigma CN * . The results indicated that there exist very slight interactions between this nitrogen pair and the C-H antibonding orbitals of nearest neighbouring hmt molecule when the sets of hmt molecules are considered.

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Spectroscopic Characterization, Crystal and Molecular Structure of [ReBr2N(PPh3)2]

Dzięgielewski J., Michalik S., Jaworska M., Kruszyński R., Kusz J.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 7

1193-1203

EN

Rhenium nitrido-complex [ReNBr2(PPh3)2] has been characterized by X-ray diffraction, IR and UV-Vis spectroscopies. The geometry optimization was carried out with the DFT method using B3LYP functional. The electronic spectrum was calculated with the TDDFT method.

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Determination of Enantiomeric Excess of Cyclophosphamide by X-Ray Powder Diffraction (XRPD)

Tadeusiak E., Kruszyński R., Misiura K.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 3

431-435

EN

The anticancer agent: cyclophosphamide 1 was studied by X-ray powder diffraction. The linear correlations between intensity/spectra from X-ray powder diffraction/and enantiomeric excess was observed.