Predominant effect of connecting atom and position of substituents on azomethine nitrogens' basicity in phthalocyanines
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11160%2F16%3A10335427" target="_blank" >RIV/00216208:11160/16:10335427 - isvavai.cz</a>
Result on the web
<a href="http://www.worldscientific.com/doi/full/10.1142/S1088424616500747" target="_blank" >http://www.worldscientific.com/doi/full/10.1142/S1088424616500747</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1142/S1088424616500747" target="_blank" >10.1142/S1088424616500747</a>
Alternative languages
Result language
angličtina
Original language name
Predominant effect of connecting atom and position of substituents on azomethine nitrogens' basicity in phthalocyanines
Original language description
The basicity of azomethine nitrogens was studied on a series of phthalocyanines (Pcs) that differed in a position of substituent, i.e. peripherally (beta-series) and non-peripherally substituted Pcs (alpha-series), and in a type of substituent (alkylsulfanyl, alkyloxy or alkyl). Appropriate 3,6- or 4,5-disubstituted phthalonitriles were prepared either by nucleophilic substitution or by Negishi coupling. Target zinc Pcs were synthesized by Linstead method. The basicity was studied by the mean of absorption and H-1 NMR spectroscopies in chloroform upon titration with trifluoroacetic acid. Equilibrium constants (log K) indicated significant difference within the series. Basicity decreased as follows: alpha-alkyloxy >> alpha-alkylsulfanyl > beta-alkyloxy > beta-alkyl > beta-alkylsulfanyl similar to alpha-alkyl with log K higher than 7 down to 2.6 M-1. Increased basicity of alpha-alkyloxy and alpha-alkylsulfanyl Pcs is caused by the stabilization of trapped hydrogen at azomethine nitrogen via hydrogen bonding and van der Waals interactions, respectively. The basicity of beta-series clearly correlated with the electronic effects of substituents. H-1 NMR studies confirmed the possibility of the weak bonding interactions in alpha-alkyloxy and alpha-alkylsulfanyl Pcs, however, the position of the H-1 NMR signal of azomethine-NH proton was even more influenced by the electronic effects of present substituents than by the weak interactions.
Czech name
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Czech description
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Classification
Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
CC - Organic chemistry
OECD FORD branch
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Result continuities
Project
<a href="/en/project/GP14-02165P" target="_blank" >GP14-02165P: Red-emitting Fluorescence Sensors Based on Azaphthalocynine Structure: Study of Aza-Crown Recognition Moiety</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2016
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Porphyrins and Phthalocyanines
ISSN
1088-4246
e-ISSN
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Volume of the periodical
20
Issue of the periodical within the volume
8-11
Country of publishing house
FR - FRANCE
Number of pages
12
Pages from-to
1122-1133
UT code for WoS article
000390248600027
EID of the result in the Scopus database
2-s2.0-84988613824