Specific solvent effects. VIII. Solvation of sodiomalonate ion pairs by the tertiary amide group

1972 ◽  
Vol 37 (14) ◽  
pp. 2253-2255
Author(s):  
H. E. Zaugg ◽  
J. E. Leonard
Keyword(s):  
Solvent Effects ◽  
Ion Pairs ◽  
Amide Group ◽  
Tertiary Amide

The Ion Associates of Methyl-, Ethyl- and Isopropyl Derivatives of Dialkylaminoethyl Dialkylamidofluorophosphate with Bromophenol Blue

1992 ◽  
Vol 57 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha
Keyword(s):  
Extraction Efficiency ◽  
Ion Pairs ◽  
Amino Nitrogen ◽  
Ion Pair ◽  
Amide Group ◽  
Bromophenol Blue ◽  
Amino Group ◽  
Methyl Ethyl ◽  
Derivatives Of

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.

scholarly journals Salt forms of the pharmaceutical amide dihydrocarbamazepine

2016 ◽  
Vol 72 (2) ◽  
pp. 155-160 ◽  
Author(s):  
Amanda R. Buist ◽  
Alan R. Kennedy
Keyword(s):  
Hydrogen Bonding ◽  
Ion Pairs ◽  
Active Pharmaceutical Ingredient ◽  
Amide Group ◽  
Supramolecular Structures ◽  
One Dimensional ◽  
Amide Bonds ◽  
Strong Acids ◽  
Salt Forms ◽  
Chloride Monohydrate

Carbamazepine (CBZ) is well known as a model active pharmaceutical ingredient used in the study of polymorphism and the generation and comparison of cocrystal forms. The pharmaceutical amide dihydrocarbamazepine (DCBZ) is a less well known material and is largely of interest here as a structural congener of CBZ. Reaction of DCBZ with strong acids results in protonation of the amide functionality at the O atom and gives the salt forms dihydrocarbamazepine hydrochloride {systematic name: [(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)(hydroxy)methylidene]azanium chloride, C15H15N2O+·Cl−}, dihydrocarbamazepine hydrochloride monohydrate {systematic name: [(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)(hydroxy)methylidene]azanium chloride monohydrate, C15H15N2O+·Cl−·H2O} and dihydrocarbamazepine hydrobromide monohydrate {systematic name: [(10,11-dihydro-5H-dibenzo[b,f]azepin-5-yl)(hydroxy)methylidene]azanium bromide monohydrate, C15H15N2O+·Br−·H2O}. The anhydrous hydrochloride has a structure with two crystallographically independent ion pairs (Z′ = 2), wherein both cations adoptsynconformations, whilst the two hydrated species are mutually isostructural and have cations withanticonformations. Compared to neutral dihydrocarbamazepine structures, protonation of the amide group is shown to cause changes to both the molecular (C=O bond lengthening and C—N bond shortening) and the supramolecular structures. The amide-to-amide and dimeric hydrogen-bonding motifs seen for neutral polymorphs and cocrystalline species are replaced here by one-dimensional polymeric constructs with no direct amide-to-amide bonds. The structures are also compared with, and shown to be closely related to, those of the salt forms of the structurally similar pharmaceutical carbamazepine.

Effects of Internal Hydrogen Bonds between Amide Groups: Protonation of Alicyclic Diamides

2003 ◽  
Vol 9 (2) ◽  
pp. 81-95 ◽  
Author(s):  
Matthias Witt ◽  
Dirk Kreft ◽  
Hans-Friedrich Grützmacher
Keyword(s):  
Hydrogen Bonds ◽  
Major Part ◽  
Kinetic Method ◽  
Amide Group ◽  
Boat Conformation ◽  
Free Rotation ◽  
Tertiary Amide ◽  
Dipole Interactions ◽  
Amide Derivatives ◽  
Entropy Effects

The proton affinity ( PA) of cyclopentane carboxamide 1, cyclohexane carboxamide 2 and their secondary and tertiary amide derivatives S1, S2, T1 and T2, was determined by the thermokinetic method and the kinetic method [ PA(1) = 888 ± 5 kJ mol−1; PA(2) = 892 ± 5 kJ mol−1; PA(S1) = 920 ± 6 kJ mol−1; PA(S2) = 920 ± 6 kJ mol−1; PA(T1) = 938 ± 6 kJ mol−1; PA(T2) = 938 ± 6 kJ mol−1]. Special entropy effects are not observed. Additionally, the effects of protonation have been studied using an advanced kinetic method for all isomers 3–7 of cyclopentane dicarboxamides and cyclohexane dicarboxamides (with the exception of cis-cyclopentane-1,2-dicarboxamide) and their bis-tertiary derivatives T3–T7 by estimating the PA and the apparent entropy of protonation Δ(Δ Sapp). Finally, the study was extended to bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxamide 8 and its bis-tertiary derivative T8, to all stereoisomers of bicyclo[2.2.1]heptane-2,3-dicarboxamide 9, their secondary and tertiary amide derivatives S9 and T9, and to endo–endo–bicyclo[2.2.1]heptane-2,5-dicarboxamide 10 and the corresponding secondary and tertiary derivatives S10 and T10. Compared with 1 and 2, all alicyclic diamides exhibit a significant increase of the PA (ΔPA) and special entropy effects on protonation. For alicyclic diamides, which can not accommodate a conformation appropriate for building a proton bridge, the values of Δ PA and Δ(Δ Sapp) are small to moderate. This is explained by ion / dipole interactions between the protonated and neutral amide group which stabilize the protonated species but hinder the free rotation of the amide groups. If any of the conformations of the alicyclic diamide allows formation of a proton bridge, Δ PA and Δ(Δ Sapp) increase considerably. A spectacular case is cis-cyclohexane-1,4-dicarboxamide 7c which is the most basic monocyclic diamide, although generation of the proton bridge requires the unfavorable boat conformation with both amide substituents at a flagpole position. A pre-orientation of the two amide groups in such a 1,4-position in 10 results in a particularly large PA of < 1000 kJ mol−1. The observation of comparable values for Δ(Δ Sapp) for linear and monocyclic diamides indicates that a major part of the entropy effects originates from freezing the free rotation of the amide groups by formation of the proton bridge. This is corroborated by observing corresponding effects during the protonation of dicarboxamides containing the rigid bicyclo[2.2.1]heptane carbon skeleton, where the only internal movements of the molecules corresponds to rotation of the amide substituents.

scholarly journals A Comprehensive Extraction Study Using a Mono-alkylated Diglycolamic Acid Extractant: Comparison Between a Secondary Amide Group and a Tertiary Amide Group

2017 ◽  
Vol 24 (2) ◽  
pp. 61-69 ◽  
Author(s):  
Tsuyoshi SUGITA ◽  
Iori FUJIWARA ◽  
Hiroyuki OKAMURA ◽  
Tatsuya OSHIMA ◽  
Yoshinari BABA ◽  
...  
Keyword(s):  
Amide Group ◽  
Secondary Amide ◽  
Tertiary Amide ◽  
Extraction Study ◽  
Acid Extractant

Solvent effects on the intramolecular conversion of trimethylsulfonium chloride to dimethyl sulfide and methyl chloride

2014 ◽  
Vol 16 (48) ◽  
pp. 26658-26671 ◽  
Author(s):  
Timm Lankau ◽  
Chin-Hui Yu
Keyword(s):  
Solvent Effects ◽  
Dimethyl Sulfide ◽  
Ion Pairs ◽  
Methyl Chloride

M05/6-311+G(2d,p) calculations reveal the role of ion pairs in the conversion of (CH3)3SCl as a function of solvent's permittivity.

scholarly journals Chiroptical molecular propellers based on hexakis(phenylethynyl)benzene through the complexation-induced intramolecular transmission of local point chirality

2014 ◽  
Vol 12 (47) ◽  
pp. 9532-9538 ◽  
Author(s):  
Ryo Katoono ◽  
Keiichi Kusaka ◽  
Shunsuke Kawai ◽  
Yuki Tanaka ◽  
Keisuke Hanada ◽  
...  
Keyword(s):  
Amide Group ◽  
Benzene Derivatives ◽  
Tertiary Amide ◽  
Local Point

We designed hexakis(phenylethynyl)benzene derivatives with a tertiary amide group on each blade to achieve a helically biased propeller arrangement.

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