search results
results of search on CRYSTALLOGRAPHY JOURNALS ONLINE
41 citations found for Duarte, T.
Search for Duarte, T. in the World Directory of Crystallographers
Results 1 to 20, sorted by name:
![c logo](https://journals.iucr.org/logos/jicons/c_36x36.png)
In this paper, we compare and discuss the very different crystal structures and supramolecular arrangements obtained when using different crystallization solvents with the same organometallic moiety. The new title tetrahydrofuran (THF) solvate, [Rh2(C2H3O2)4(C27H36N2)2]·4C4H8O, is compared with the toluene trisolvate reported previously by us [Góis, Trindade, Veiros, Andre, Duarte, Afonso, Caddick & Cloke (2007). Angew. Chem. Int. Ed. 46, 5750–5753]. The molecular structures of the two complex molecules display a similar conformation, but due to the presence of different solvent molecules, the two solvates crystallize in different space groups and exhibit quite diverse supramolecular assemblies. The toluene solvate crystallizes in the triclinic space group P
, while in the presence of THF, the monoclinic P21/c space group is obtained, with the complex molecule residing on an inversion centre. The resulting crystal packing displays no classical hydrogen bonds but different supramolecular synthons give rise to different packing motifs. In this work, we highlight the different supramolecular architectures obtained when organometallic moieties crystallize with different solvent molecules. We compare the novel structure of the THF derivative with that of the toluene solvate of a dirhodium(II) complex belonging to a new family of catalyst compounds exhibiting very high performance in arylation processes.
![\overline{1}](http://journals.iucr.org/c/issues/2008/10/00/hj3081//teximages/hj3081fi1.gif)
![c logo](https://journals.iucr.org/logos/jicons/c_36x36.png)
A second polymorphic form (form II) of the previously reported 1,4,7-tris(p-tolylsulfonyl)-1,4,7-triazacyclononane (form I), C27H33N3O6S3, is presented. The molecular structures of the two forms display very different conformations, thus prompting the two forms to crystallize in two different space groups and exhibit quite diverse crystal structure assemblies. Form I crystallizes in the triclinic space group P
, while form II crystallizes in the monoclinic space group P21/n. The main differences between the two molecular structures are the conformations of the p-tosyl groups relative to each other and to the macrocyclic ring. The resulting crystal packing displays no classical hydrogen bonds, but different supramolecular synthons give rise to different packing motifs.
![\overline{1}](http://journals.iucr.org/c/issues/2007/10/00/hj3048//teximages/hj3048fi1.gif)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![c logo](https://journals.iucr.org/logos/jicons/c_36x36.png)
In the title complex, trans-{2,2′-[cyclohexane-1,2-diylbis(nitrilomethylidyne)]diphenolato-κ4O,N,N′,O′}nickel(II)–chloroform (1/1), [Ni(C20H20N2O2)]·CHCl3, the Ni atom has a square-planar geometry, slightly tetrahedrally distorted. The Ni—N and Ni—O bonding distances are within the expected ranges for Ni–Schiff base derivatives. The diimine bridge has a gauche conformation with the cyclohexyl ring almost coplanar with the NiN2O2 plane. The complex molecules pack in dimers with an Ni
Ni distance of 3.59 (1) Å and form a three-dimensional structure displaying a herring-bone configuration. Channels are occupied by solvent molecules, which are involved in C—H
O hydrogen bonds with the ligand O atoms.
![...](/logos/entities/ctdot_rmgif.gif)
![...](/logos/entities/ctdot_rmgif.gif)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![c logo](https://journals.iucr.org/logos/jicons/c_36x36.png)
The title compound, [1,2-bis(diphenylphosphino)ethane](η5-cyclopentadienyl)(4-nitrobenzonitrile)iron(II) iodide, [Fe(η5-C5H5)(C7H4N2O2)(C26H4P2)]I, crystallizes in the non-centrosymmetric space group Cc, which is a promising result for obtaining quadratic non-linear optical properties. However, the packing shows that the iodide counter-ion promotes the cancellation of almost all the dipoles, resulting in a supramolecular motif of cationic chains aligned in opposite directions making an angle of 35.2°. The use of PF6− as counter-ion induces the crystallization of the complex in a centrosymmetric space group. These results show that the introduction of different counter-ions, of different size and geometry, allows specific and directional intermolecular interactions that can determine the formation of a particular type of crystal packing.
![c logo](https://journals.iucr.org/logos/jicons/c_36x36.png)
The title compound, (
5-cyclopentadienyl)(4-nitrobenzonitrile-
N)(trimethylphosphine-
P)(triphenylphosphite-
P)iron(II) hexafluorophosphate, [Fe(C5H5)(C7H4N2O2)(C18H15O3P)(C3H9P)]PF6, has been characterized by spectroscopic and X-ray diffraction in order to evaluate the tuning of the electron density at the metal centre and the extension of the
delocalization on the molecule due to the presence of phosphite and phosphine co-ligands. The compound crystallizes in the centrosymmetric space group P21/c, which destroys the possibility of exhibiting any quadratic non-linear optical properties. The packing shows a supramolecular zigzag chain of antiparallel cations connected via the PF6- anions through C-H
F
- interactions, with H
F distances ranging from 2.39 to 2.67 Å. Each zigzag chain is composed of isomeric organometallic fragments containing either R or S molecules. These chains are connected through weak intermolecular C-H
C interactions, forming a two-dimensional plane parallel to (101).
![[eta]](/logos/entities/eta_rmgif.gif)
![[kappa]](/logos/entities/kappa_rmgif.gif)
![[kappa]](/logos/entities/kappa_rmgif.gif)
![[kappa]](/logos/entities/kappa_rmgif.gif)
![[pi]](/logos/entities/pi_rmgif.gif)
![...](/logos/entities/ctdot_rmgif.gif)
![[delta]](/logos/entities/delta_rmgif.gif)
![...](/logos/entities/ctdot_rmgif.gif)
![...](/logos/entities/ctdot_rmgif.gif)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)
![c logo](https://journals.iucr.org/logos/jicons/c_36x36.png)
The structure of the title compound, [Ti(C2H6N)2(C6H8N)Cl], displays a
5-coordination mode for the pyrrolyl ring, confirmed by the values of the slip parameter [0.073 (9) Å] and the fold angle [4.6 (6)°]. This coordination is confirmed by NMR data, which point to the involvement of the complex in a fluxional process in solution above 285 K, passing through an intermediate involving simultaneously a metal-azaallyl and a metal-olefin bond.
![[eta]](/logos/entities/eta_rmgif.gif)
![a logo](https://journals.iucr.org/logos/jicons/a_36x36.png)