Optimized synthesis of a tert-butyl-phenyl-substituted tetrapyridophenazine ligand and its Ru(ii) complexes and determination of dimerization behaviour of the complexes through supramolecular “Fingerhakel”

2015 ◽  
Vol 44 (19) ◽  
pp. 8889-8905 ◽  
Author(s):  
K. Ritter ◽  
C. Pehlken ◽  
D. Sorsche ◽  
S. Rau

A high dimerization constant of a ruthenium complex is observed with the aid of 1H-NMR spectroscopy. The solid state molecular structure indicates that multiple π-interactions are the reason for strong dimerization.

2021 ◽  
Vol 76 (2) ◽  
pp. 103-118
Author(s):  
Erik Wächtler ◽  
Robert Gericke ◽  
Theresa Block ◽  
Birgit Gerke ◽  
Rainer Pöttgen ◽  
...  

Abstract The compounds Pn(pyS)3 (Pn = P, As, Sb, Bi) were synthesized from the respective chloride (Pn = P, As, Sb) or nitrate (Bi), pyridine-2-thiol (pySH) and triethylamine (NEt3) as a supporting base in THF (P, Sb), CHCl3 (As) or methanol (Bi). Sb(pyS)3 was also obtained from the reaction of SbCl3 with LipyS (prepared in situ) in methanol. The compounds Sb(pyS)2Ph and Sb(pyS)Ph2 were prepared in a one-pot reaction starting from SbCl3 and SbPh3 (1:1 ratio). Upon Cl/pyS substitution, the resulting reaction mixture allows for a facile separation of the products in hot hexane. P(pyS)3 and As(pyS)3 crystallize isostructurally to the reported structure of Sb(pyS)3 with κ-S-bound pyS ligands. These crystal structures feature close Pn···Pn contacts which are most pronounced for the arsenic derivative. Bi(pyS)3 adopts a different molecular structure in the solid state, which features two chelating (κ 2-S,N-pyS) ligands and a κ-S-bound ligand. The presence of N→Bi interactions between the nitrogen atom of the κ-S-pyS ligand and the Bi atom of another molecule renders this structure a polymer chain along the crystallographic b axis with Bi⋅⋅⋅Bi van-der-Waals contacts. The structures of this set of Pn(pyS)3 compounds were also studied in solution using 1H NMR spectroscopy, revealing equivalent pyS ligands in discrete Pn(pyS)3 molecules. The molecular structure of Sb(pyS)Ph2 was optimized by quantum chemical methods, and a comparison with the structures reported for the other Sb/pyS/Ph combinations reveals Sb(pyS)2Ph to feature the strongest Sb···N interactions with the κ-S-pyS ligand. The results of 1H NMR spectroscopic investigations of the compounds Sb(pyS) x Ph3–x (x = 3–0) suggest the Ph protons in ortho position to be incorporated into intramolecular C–H···S contacts for x = 2 and 1. Natural localized molecular orbital (NLMO) calculations were employed in order to gain insights into the electronic situations of the Pn atoms and Pn–R bonds (R = S, C), especially for the effects caused by formal substitution of Pn in the compounds Pn(pyS)3 and the ligand patterns in the compounds Sb(pyS) x Ph3–x (x = 3–0). For the latter series of compounds, the electronic situation of the Sb atom was further studied by 121Sb Mössbauer spectroscopy, providing a correlation between the calculated electron density at Sb [ρ(0)] and the experimentally observed isomer shift δ. The missing link between group 15 and group 13 metal compounds of the type M(pyS)3, compound Al(pyS)3, was synthesized in this work. In the solid state (confirmed crystallographically), the mer isomer of this tris-chelate complex with distorted octahedral Al coordination sphere was found. This coordination mode was confirmed for the solution state (CDCl3) by 1H and 13C NMR spectroscopy at T = −40 °C.


1988 ◽  
Vol 7 (2) ◽  
pp. 552-555 ◽  
Author(s):  
Walter. Bauer ◽  
P. A. A. Klusener ◽  
Sjoerd. Harder ◽  
J. A. Kanters ◽  
A. J. M. Duisenberg ◽  
...  

Methods ◽  
2018 ◽  
Vol 138-139 ◽  
pp. 26-38 ◽  
Author(s):  
Antoine Loquet ◽  
Nadia El Mammeri ◽  
Jan Stanek ◽  
Mélanie Berbon ◽  
Benjamin Bardiaux ◽  
...  

2008 ◽  
pp. 339-343
Author(s):  
Axel Kretschmer ◽  
Robert A. Drake ◽  
Simeon J. Bones ◽  
Michael Neidhoefer ◽  
Manfred Wilhelm ◽  
...  

2011 ◽  
Vol 89 (7) ◽  
pp. 854-862
Author(s):  
Glenn A. Facey ◽  
Ilia Korobkov

The tri-ortho-thymotide (TOT) clathrates of dibromo- and dichloromethane were characterized by single crystal X-ray diffraction at 200 K and solid-state 2H NMR spectroscopy as a function of temperature. The host structure was found to be typical of other cage-type TOT clathrates. The X-ray results showed a substantial amount of disorder among the guest molecules. In both clathrates, multiple guest molecule positions could be modeled. The heavy atoms of all the guest molecule positions lie approximately in the same plane, with some out-of-plane distortion. The guest molecules were of two different types in positions symmetric about the crystallographic twofold rotation axis: type A guests, with carbon atoms well removed from the crystallographic twofold axis, and type B guests, with carbon atoms very close to the twofold axis. The 2H NMR spectra for the guests confirmed that the disorder was dynamic. The experimental results could be accounted for by the presence of three simultaneous types of molecular motion, all fast with respect to the 2H quadrupolar interaction: (i) twofold molecular flips about the molecular C2 symmetry axis, (ii) exchange between the type A and type B sites in a single plane, and (iii) a two-site libration of the plane containing the heavy atoms of the A and B guest sites with a temperature-dependent amplitude.


Author(s):  
Rosa María Claramunt ◽  
María Dolores Santa María ◽  
Isabelle Forfar ◽  
Francisco Aguilar-Parrilla ◽  
María Minguet-Bonvehí ◽  
...  

2014 ◽  
Vol 70 (6) ◽  
pp. 555-561 ◽  
Author(s):  
Kamlakar Avasthi ◽  
Lakshmi Shukla ◽  
Ruchir Kant ◽  
Krishnan Ravikumar

The butylidene-linker models 1-[2-(2,6-dimethylsulfanyl-9H-purin-9-yl)-2-methylidenepropyl]-4,6-bis(methylsulfanyl)-1H-pyrazolo[3,4-d]pyrimidine, C18H20N8S4, (XI), 7,7′-(2-methylidenepropane-1,3-diyl)bis[3-methyl-2-methylsulfanyl-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one], C20H22N6O2S2, (XIV), and 7-[2-(4,6-dimethylsulfanyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)-2-methylidenepropyl]-3-methyl-2-methylsulfanyl-3H-pyrrolo[2,3-d]pyrimidin-4(7H)-one, C19H21N7OS3, (XV), show folded conformations in solution, as shown by1H NMR analysis. This folding carries over to the crystalline state. Intramolecular π–π interactions are observed in all three compounds, but only (XIV) shows additional intramolecular C—H...π interactions in the solid state. As far as can be established, this is the first report incorporating the pyrrolo[2,3-d]pyrimidine nucleus for such a study. In addition to the π–π interactions, the crystal structures are also stabilized by other weak intermolecular C—H...S/N/O and/or S...N/S interactions.


1982 ◽  
Vol 37 (11) ◽  
pp. 1461-1471 ◽  
Author(s):  
Reinhold Tacke ◽  
Haryanto Linoh ◽  
Moayad T. Attar-Bashi ◽  
William S. Sheldrick ◽  
Ludger Ernst ◽  
...  

The potentially curare-like silicon compounds 8a-8f wore synthesized and investigated with respect to their structure-activity relationships. The conformations of the com­pounds in the solid state and in solution were studied by X-ray diffraction analysis (8a-8e) and 1H NMR spectroscopy (8a-8f), respectively. The muscle relaxing properties of 8a-8f were investigated on the mouse. The observed structure-activity relationships are not in accordance with the classical “14 Å model” for neuromuscular blocking agents.


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