scholarly journals Intra-Cation versus Inter-Cation π-Contacts in [Cu(P^P)(N^N)][PF6] Complexes

Crystals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
Francesca Mazzeo ◽  
Fabian Brunner ◽  
Alessandro Prescimone ◽  
Edwin C. Constable ◽  
Catherine E. Housecroft

A series of [Cu(POP)(N^N][PF6] and [Cu(xantphos)(N^N][PF6] compounds has been prepared and characterized in which POP = bis[2-(diphenylphosphanyl)phenyl]ether (IUPAC PIN oxydi(2,1-phenylene)bis(diphenylphosphane), xantphos = 4,5-bis(diphenylphosphanyl)-9,9-dimethyl-9H-xanthene (IUPAC PIN (9,9-dimethyl-9H-xanthene- 4,5-diyl)bis(diphenylphosphane)) and the N^N ligands are 4-(4-bromophenyl)-6,6′-dimethyl-2,2′- bipyridine (1), 5,5′-bis(3-methoxyphenyl)-6-methyl-2,2′-bipyridine (2), and 6-benzyl-2,2′-bipyridine (3). The single crystal structures of [Cu(xantphos)(1)][PF6]·CH2Cl2, [Cu(xantphos)(2)][PF6]·CH2Cl2 and [Cu(POP)(3)][PF6]·0.5H2O were determined by X-ray diffraction. Each complex contains a copper(I) ion in a distorted tetrahedral environment with chelating N^N and P^P ligands. In the [Cu(xantphos)(1)]+ and [Cu(xantphos)(2)]+ cations, there are face-to-face π-stackings of bpy and PPh2 phenyl rings (i.e., between the ligands); in addition in [Cu(xantphos)(2)][PF6]·CH2Cl2, inter-cation π-embraces lead to the formation of infinite chains as a primary packing motif. In [Cu(POP)(3)][PF6]·0.5H2O, centrosymmetric pairs of [Cu(POP)(3)]+ cations engage in C–H…π (phenyl to bpy) and offset face-to-face (bpy…bpy) contacts. The electrochemical and photophysical properties of the compounds containing ligands 1 and 2 are reported. They are green or yellow emitters in the solid-state (λem in the range 535–577 nm) with values for the photoluminescence quantum yield (PLQY) in the range 19%–41%.

2011 ◽  
Vol 34 (5-6) ◽  
pp. 153-153
Author(s):  
Libasse Diop

Abstract Solid-state and solution 117Sn nuclear magnetic resonance studies of C2O4(SnPh3)2 have been carried out and found to be in good agreement with the tetrahedral environment of the tin (IV) atom as found from the solid state structure, previously determined by a single crystal X-ray diffraction analysis.


2015 ◽  
Vol 71 (8) ◽  
pp. 664-666 ◽  
Author(s):  
Rüdiger W. Seidel ◽  
Richard Goddard

The simplest alkyl aryl ether, anisole (methoxybenzene), C7H8O, is a feedstock chemical and is widely used in the pharmaceutical industry. The structure of anisole at 100 K, as determined by single-crystal X-ray analysis, is reported. A crystal (m.p. 236 K) suitable for X-ray diffraction was obtained from the melt. The title compound crystallizes in the centrosymmetric space groupP21/cwith two molecules in the asymmetric unit (Z′ = 2). Both crystallographically distinct molecules adopt a virtually flat (Cs-symmetric) conformation. The arrangement of the molecules in the solid state appears to be governed by close packing. No face-to-face π–π stacking of the molecules is observed, but rather edge-to-face interactions result in a herringbone packing motif.


2019 ◽  
Vol 74 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Edith Alig ◽  
Isabelle Georg ◽  
Inge Sänger ◽  
Lothar Fink ◽  
Matthias Wagner ◽  
...  

AbstractThe donor-free potassium silanide K[SiPh3] was prepared by the reaction of hexaphenyldisilane, Ph3Si–SiPh3, with potassium metal in benzene at room temperature. The solid-state structure, determined by powder X-ray diffraction consists of {K[SiPh3]}2 units, which interact with adjacent dimers to form an infinite chain along the crystallographic c axis (orthorhombic, space group Cmc21, Z=4). The structure features short contacts between the π system of the phenyl rings and the potassium atoms of neighbouring K[SiPh3] units.


Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 889
Author(s):  
Torvid Feiler ◽  
Biswajit Bhattacharya ◽  
Adam A. L. Michalchuk ◽  
Vincent Schröder ◽  
Emil List-Kratochvil ◽  
...  

Tuning and controlling the solid-state photophysical properties of organic luminophore are very important to develop next-generation organic luminescent materials. With the aim of discovering new functional luminescent materials, new cocrystals of 9-anthracene carboxylic acid (ACA) were prepared with two different dipyridine coformers: 1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)ethane. The cocrystals were successfully obtained by both mechanochemical approaches and conventional solvent crystallization. The newly obtained crystalline solids were characterized thoroughly using a combination of single crystal X-ray diffraction, powder X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. Structural analysis revealed that the cocrystals are isostructural, exhibiting two-fold interpenetrated hydrogen bonded networks. While the O–H···N hydrogen bonds adopts a primary role in the stabilization of the cocrystal phases, the C–H···O hydrogen bonding interactions appear to play a significant role in guiding the three-dimensional assembly. Both π···π and C–H···π interactions assist in stabilizing the interpenetrated structure. The photoluminescence properties of both the starting materials and cocrystals were examined in their solid states. All the cocrystals display tunable photophysical properties as compared to pure ACA. Density functional theory simulations suggest that the modified optical properties result from charge transfers between the ACA and coformer molecules in each case. This study demonstrates the potential of crystal engineering to design solid-state luminescence switching materials through cocrystallization.


2016 ◽  
Vol 72 (11) ◽  
pp. 861-866
Author(s):  
Rüdiger W. Seidel ◽  
Richard Goddard ◽  
Thomas Mayer-Gall ◽  
Iris M. Oppel

Porphyrin assemblies display interesting photophysical properties and a relatively high thermal stability. Moreover,meso-functionalized porphyrins with virtually fourfold symmetry can be relatively readily synthesized from pyrrole and the appropriate aldehyde. A number of metallo derivatives of 5,10,15,20-tetrakis(4-cyanophenyl)porphyrin, where the N atom of the linear cyano group can act both as a donor for coordination bonds or as an acceptor for hydrogen bonds, have been structurally characterized by single-crystal X-ray analysis. The supramolecular and structural chemistry of the corresponding 2- and 3-cyanophenyl isomers of the parent porphyrin, however, has remained largely unexplored. The crystal structure of [5,10,15,20-tetrakis(3-cyanophenyl)porphyrinato]copper(II) (CuTCNPP) nitrobenzene trisolvate, [Cu(C48H24N8)]·3C6H5NO2, has been determined at 80 K by synchrotron single-crystal X-ray diffraction. CuTCNPP exhibits aC2h-symmetric ααββ conformation, despite an unsymmetrical crystal environment, and is situated on a crystallographic centre of symmetry. The CuIIion adopts a genuine square-planar coordination by the four pyrrole N atoms. The 24-membered porphyrin ring system shows no marked deviation from planarity. In the crystal, the CuTCNPP molecules and two nitrobenzene molecules are face-to-face stacked in an alternating fashion, resulting in corrugated layers. The remaining nitrobenzene guest molecule per CuTCNPP resides in the region between four neighbouring columnar stacks of CuTCNPP and sandwiched nitrobenzene molecules, and is disordered over four positions about a centre of symmetry.


CrystEngComm ◽  
2005 ◽  
Vol 7 (43) ◽  
pp. 269 ◽  
Author(s):  
Katharine F. Bowes ◽  
Ian P. Clark ◽  
Jacqueline M. Cole ◽  
Matthew Gourlay ◽  
Alexandra M. E. Griffin ◽  
...  

2009 ◽  
Vol 64 (9) ◽  
pp. 989-994 ◽  
Author(s):  
Tao Xie ◽  
Wolfgang Brockner ◽  
Mimoza Gjikaj

2,3,5-Triphenyltetrazolium hexachlorophosphate, [C19H15N4]+[PCl6]−, [TPT]+[PCl6]− (1), and 2,3,5-triphenyltetrazolium dichlorophosphate(V), [C19H15N4]+[PO2Cl2]−, [TPT]+[PO2Cl2]− (2), were synthesized by reactions of anhydrous 2,3,5-triphenyltetrazolium chloride, [TPT]+Cl−, and 2,3,5-triphenyltetrazolium chloride monohydrate [TPT]+Cl− ・H2O, with PCl5 in dry acetonitrile, and their crystal structures were determined by single-crystal X-ray diffraction analysis. In the title compounds, the [TPT]+ cations show a face-to-face stacked orientation between the phenyl rings of neighboring molecules, which is caused by intermolecular π ・ ・ ・π interactions. The crystal structure of compound 1 consists of layers of 2,3,5-triphenyltetrazolium cations and hexachlorophosphate anions. In compound 2 the tetrahedral [PO2Cl2]− anions exhibit approximate C2v symmetry with P-O bond lengths from 1.454 to 1.463 Å and P-Cl bond lengths from 2.038 to 2.050 Å . The Raman spectrum of compound 1 was recorded, and the assignment of the [PCl6]− Raman modes is proposed.


Author(s):  
Kenneth M. Richter ◽  
John A. Schilling

The structural unit of solid state collagen complexes has been reported by Porter and Vanamee via EM and by Cowan, North and Randall via x-ray diffraction to be an ellipsoidal unit of 210-270 A. length by 50-100 A. diameter. It subsequently was independently demonstrated by us in dog tendon, dermis, and induced complexes. Its detailed morphologic, dimensional and molecular weight (MW) aspects have now been determined. It is pear-shaped in long profile with m diameters of 57 and 108 A. and m length of 263 A. (Fig. 1, tendon, KMnO4 fixation, Na-tungstate; Fig. 2a, schematic of unit in long, C, and x-sectional profiles of its thin, xB, and bulbous, xA portions; Fig. 2b, tendon essentially unmodified by ether and 0.4 N NaOH treatment, Na-tungstate). The unit consists of a uniquely coild cable, c, of ṁ 22.9 A. diameter and length of 2580-3316 A. The cable consists of three 2nd-strands, s, each of m 10.6 A.


Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.


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