Wechselwirkungen in Kristallen, 35 [ 1, 2] Einkristallzüchtung von Na⊕⊖C(NO2)3 [***] aus Etherlösungen zu einem polymeren Band [(Na⊕⊖C(NO2)3) Dioxan]∞ und einem Lösungsmittel-getrennten Ionenpaar [(Na⊕/18-Krone-6)(THF)2]⊕ [(Na⊕/18-Krone-6)(ONO-C⊖(NO2)2)2]⊖ / Interactions in Crystals, 35 [1, 2] Single Crystal Growths of Na⊕⊖C(NO2)3[***] from Ether Solutions to a Polymer Band [(Na⊕⊖C(NO2)3)Dioxane]∞ and to a Solvent-Separated Ion Pair [(Na⊕/18-Crown-6)(THF)2]⊕[(Na⊕/18-Crown-6)(ONO-C⊖(NO2)2)2]⊖

1994 ◽  
Vol 49 (8) ◽  
pp. 1012-1020 ◽  
Author(s):  
H. Bock ◽  
T. Hauck ◽  
C. Näther ◽  
Z. Havlas
Keyword(s):  
Single Crystal ◽  
Charge Distribution ◽  
Quantum Chemical Calculations ◽  
Sodium Salt ◽  
Quantum Chemical ◽  
Ion Pair ◽  
Hazard Warning

The sodium salt of the most simple polynitro-substituted hydrocarbon anion. Na⊕⊖C(NO2)3, (for a hazard warning cf. [***]) crystallizes from ether solutions without and with addition of 18-crown-6 either in a polymer band. [(Na⊕⊖C(NO2)3)dioxane]∞, or as a solvent- separated ion pair, [(Na⊕/18-crown-6)(THF2]⊕[(Na⊕/18-crown-6)(O2N-C⊖(NO2)2)2]⊖. The Na⊕ cations are each 8-fold coordinated in hexagonal bipyramidal arrangement. According to extensive quantum-chemical calculations based on the structure coordinates, the formation of these novel salts can be traced back to the charge distribution in the anions ⊖C(NO2)3. which due to negatively charged oxygen centers are favorable complex ligands. The structure determining effects of solvation are discussed.

scholarly journals Synthesis of Bis(Carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 (n = 0, 1) and Attempt of Synthesis of Gadolinium Bis(Dicarbollide)

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1321
Author(s):  
Yasunobu Asawa ◽  
Aleksandra V. Arsent’eva ◽  
Sergey A. Anufriev ◽  
Alexei A. Anisimov ◽  
Kyrill Yu. Suponitsky ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
X Ray Diffraction ◽  
Stable Conformation ◽  
Acyl Chlorides ◽  
X Ray ◽  
Cesium Fluoride ◽  
The Stability

Bis(carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 (n = 0, 1) were prepared by the reactions of the corresponding carboranyl acyl chlorides with ethylenediamine. Crystal molecular structure of 1,1′-μ-(CH2NH(O)C-1,2-C2B10H11)2 was determined by single crystal X-ray diffraction. Treatment of bis(carboranyl)amides 1,1′-μ-(CH2NH(O)C(CH2)n-1,2-C2B10H11)2 with ammonium or cesium fluoride results in partial deboronation of the ortho-carborane cages to the nido-carborane ones with formation of [7,7′(8′)-μ-(CH2NH(O)C(CH2)n-7,8-C2B9H11)2]2−. The attempted reaction of [7,7′(8′)-μ-(CH2NH(O)CCH2-7,8-C2B9H11)2]2− with GdCl3 in 1,2-dimethoxy- ethane did not give the expected metallacarborane. The stability of different conformations of Gd-containing metallacarboranes has been estimated by quantum-chemical calculations using [3,3-μ-DME-3,3′-Gd(1,2-C2B9H11)2]− as a model. It was found that in the most stable conformation the CH groups of the dicarbollide ligands are in anti,anti-orientation with respect to the DME ligand, while any rotation of the dicarbollide ligand reduces the stability of the system. This makes it possible to rationalize the design of carborane ligands for the synthesis of gadolinium metallacarboranes on their base.

Strukturen ladungsgestörter oder räumlich überfüllter Moleküle, 80 [1 - 3] Strukturänderungen von p-Benzochinon durch Donator- und Akzeptor-Substituenten

1996 ◽  
Vol 51 (2) ◽  
pp. 153-171 ◽  
Author(s):  
Hans Bock ◽  
Sabine Nick ◽  
Wolfgang Seitz ◽  
Christian Näther ◽  
Jan W. Bats
Keyword(s):  
Charge Distribution ◽  
Quantum Chemical Calculations ◽  
Satisfactory Agreement ◽  
Quantum Chemical ◽  
Structural Changes ◽  
Structural Data ◽  
Semiempirical Calculations ◽  
Reduction Potentials ◽  
Donor Acceptor ◽  
Structural Summary

Abstract The structures of seven di- or tetrasubstituted p-benzoquinone derivatives O=C(XC=CH )2C=O and O=C(XC=CX)2C=O with substituents X = -OCH3, -N(CH2)5, - N(CH2CH2)2O, -Cl, -CN and -⊕N(HC=CH)2C-N(CH3)2 are presented and discussed in comparison with published ones substituted by X = -Si(CH3)3, -C6H5, -N(CH3)2, -⊕N(HC=CH)2CN(CH3)2, -O⊖ , and - NO2. Based on the introduction, in which halfwave-reduction potentials, geometry-optimized quantum-chemical calculations on substituent perturbation and known structural data of p-benzoquinone derivatives are used to characterize their molecular ground states. The structural changes indicate how substituent perturbations might be rationalized. Of the categories defined - imperturbed, donor, donor/acceptor and acceptor perturbed - the donorsubstituted p-benzoquinones do exhibit the largest differences, often called cyanine distorsion. In very satisfactory agreement with extensive semiempirical calculations, all effects determined experimentally are discussed in terms of varying charge distribution. With respect to the biochemical importance of p-benzoquinone derivatives, this first structural summary points out important facets.

scholarly journals Synthesis and Structure of Methylsulfanyl Derivatives of Nickel Bis(Dicarbollide)

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4449 ◽  
Author(s):  
Sergey A. Anufriev ◽  
Kyrill Yu. Suponitsky ◽  
Oleg A. Filippov ◽  
Igor B. Sivaev
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
X Ray Diffraction ◽  
Gauche Conformation ◽  
X Ray ◽  
Derivatives Of ◽  
Transoid Conformation

Symmetrically and unsymmetrically substituted methylsulfanyl derivatives of nickel(III) bis(dicarbollide) (Bu4N)[8,8′-(MeS)2-3,3′-Ni(1,2-C2B9H10)2], (Bu4N)[4,4′-(MeS)2-3,3′-Ni(1,2-C2B9H10)2], and (Bu4N)[4,7′-(MeS)2-3,3′-Ni(1,2-C2B9H10)2] were synthesized, starting from [Ni(acac)2]3 and the corresponding methylsulfanyl derivatives of nido-carborane (Bu4N)[10-MeS-7,8-C2B9H11] and (Bu4N)[10-MeS-7,8-C2B9H11]. Structures of the synthesized metallacarboranes were studied by single-crystal X-ray diffraction and quantum chemical calculations. The symmetrically substituted 8,8′-isomer adopts transoid conformation stabilized by two pairs of intramolecular C–H···S hydrogen bonds between the dicarbollide ligands. The unsymmetrically substituted 4,7′-isomer adopts gauche conformation, which is stabilized by two nonequivalent C–H···S hydrogen bonds and one short chalcogen B–H···S bond (2.53 Å, −1.4 kcal/mol). The gauche conformation was found to be also preferred for the 4,7′-isomer.

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