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Crystal Structure, Magnetic Exchange Interaction, and DFT Study of 2,2′‐(1‐Oxidopyridine‐2,6‐diyl)bis[4,5‐dihydro‐4,4,5,5‐tetramethyl‐3‐oxido‐1 H ‐imidazol‐1‐oxyl] Hydrate
Author(s) -
Zhang Lei,
Liu ZhiLiang,
Weng LinHong,
Liao DaiZheng,
Jiang ZongHui,
Yan ShiPing,
Shen PanWen,
Baumgarten Martin
Publication year - 2001
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(20010418)84:4<834::aid-hlca834>3.0.co;2-y
Subject(s) - chemistry , monoclinic crystal system , antiferromagnetism , hydrate , crystallography , density functional theory , crystal structure , moiety , ground state , magnetic susceptibility , nitroxide mediated radical polymerization , pyridine , singlet state , crystal (programming language) , stereochemistry , computational chemistry , medicinal chemistry , excited state , condensed matter physics , organic chemistry , physics , radical polymerization , computer science , programming language , copolymer , polymer , quantum mechanics , nuclear physics
The structure of a novel oxido‐aminoxyl (=`nitronyl nitroxide') biradical, 2,2′‐(1‐oxidopyridine‐2,6‐diyl)bis[4,5‐dihydro‐4,4,5,5‐tetramethyl‐3‐oxido‐1 H ‐imidazol‐1‐oxyl] hydrate ( 1 ⋅H 2 O) was established by X‐ray analysis in the solid state: monoclinic, space group P 2 1 / c , Z =4 with a =12.621(4), b =15.704(5), and c =13.001(4) Å, and β =115.202(6)°. Variable‐temperature magnetic susceptibilities show a weak antiferromagnetic interaction between the two oxido‐substituted aminoxyl moieties of 1 , indicative of a singlet ground state. AM1 Calculations located minima for the possible structure based on the X‐ray crystal structure. A hybride density‐functional‐theory calculation with the UB3LYP method from the X‐ray crystal structure establishes the same spin sign in the two aminoxyl moieties and shows that a small spin density is localized at the C‐atoms of the pyridine moiety. These theoretic results are in good agreement with the determined weak antiferromagnetic interaction of 1 .