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Tetrazoles crystal structures

The mononuclear hexakis(l-alkyl-tetrazole)iron(II) compounds with various anions have been extensively studied. It appears that the spin crossover characteristics of compounds with different alkyl substituents attached to N-1 of the tetrazole heavily depend on the crystal structure features. The transitions may be abrupt or rather gradual, complete or only involving a fraction of the Fe(II) ions, and the Tm values lie in the range 63-204 K [2c, 2f, 2g, 74-81]. Interest in these systems has focused on their suitability for detailed studies of the LIESST effect (A. Hauser, this volume). [Pg.153]

Treatment of a THF solution of trimethylenetetrazole 44 with a solution of BuLi in hexane affords a yellow to orange solution of the lithiated tetrazole 45 (structure tentatively assigned). Alkylation with Mel gives 7-methyl-6,7-dihydro-5//-pynolo[ 1,2-c]tetrazolc 46 in 73% yield. Quaternization of 46 with dimethyl sulfate affords a mixture (3 1) of tetrazolium salts 47 and 48 from which PFg- salts were obtained by crystallization (Scheme 2) <1997MI671>. [Pg.950]

X-ray crystal structures, 5, 796 Tetrazole, 5-bromo-l-methyl-reactions, 5, 105, 806 Tetrazole, 5-chloro-solubility, 5, 803 Tetrazole, 5-cyano-2-phenyl-reactions, 5, 820 Tetrazole, 5-cyanovinyl-as propellants, 5, 837 Tetrazole, 1,5-dialkyl-analeptic activity, 5, 834 Tetrazole, 5-dialkylamino-benzylation, 5, 793, 818 Tetrazole, 1,3-diaryl-5-oxide... [Pg.854]

When aqueous solutions of the complexes [Co(NH3)5(N=CR)]3+ (R=Me or Ph) are treated with an excess of NaN3 at pH 5-6 (to prevent base hydrolysis to the amido complex) tetrazole complexes are formed (Scheme 17).32 The formation of 5-methyltetrazoIe from sodium azide and acetonitrile requires a reaction time of 25 h at 150 °C323 compared with only 2 h at ambient temperature for coordinated acetonitrile. The subsequent conversion of the N -bonded complex to an N2-bonded complex has been confirmed as the latter complex has been prepared and its crystal structure determined.324... [Pg.450]

The crystal structures of a series of bioactive 1-substituted tetrazoles have been determined. Thus, May and Abell have described the structures of peptidomimetic 48 and some of its derivatives 49 <2001CC2080, 2002J(P1)172>. [Pg.268]

Several [CoL(NH3)5]3+ and m-[CoL(X)(en)2]2+ complexes have been prepared (Table 26) and some crystal structures are available (Table 25). Pentaammine complexes are easily made from [Co(DMSO)(NH3)5](C104)3, and there is no need to use a better leaving group.340,341 The physical properties ( H NMR, visible-UV, 13C NMR, pATa) for both systems (L = imH) have been comprehensively documented.341,342 The acidity of the N3 proton in (65) is enhanced by coordination and the imidazolate anion is readily accessible (pXa 10.0 vs. 14.1 for imH). Several deprotonated bimetallic bridged species have been prepared and structure (66) has been put forward as a model for heterobiometallic protein centres.343 The tetrazole complexes (68) exist predominantly in the anionic form (pA 1-2)351 and preparation normally gives the N(2)-bonded form. However Ellis and Purcell352 have prepared the N(l) isomer by reacting a coordinated nitrile with N3 ion at pH 5 (equation 52). Properties of both isomers are available.351... [Pg.697]

A wide range of stable metallic and molecular complexes of tetrazole systems, e.g. (3), has been described <77AHC(21)323) and many crystal structures have been determined for these complexes. The tetrazole ring is invariably planar with bond lengths characteristic of an aromatic system. Tetrazolate anion salts (4) are stable aromatic systems and they have been used widely as nucleophiles in synthetic reactions. [Pg.793]


See other pages where Tetrazoles crystal structures is mentioned: [Pg.854]    [Pg.855]    [Pg.34]    [Pg.228]    [Pg.154]    [Pg.159]    [Pg.257]    [Pg.589]    [Pg.627]    [Pg.628]    [Pg.635]    [Pg.653]    [Pg.670]    [Pg.672]    [Pg.678]    [Pg.92]    [Pg.63]    [Pg.185]    [Pg.221]    [Pg.227]    [Pg.855]    [Pg.92]    [Pg.168]    [Pg.264]    [Pg.265]    [Pg.265]    [Pg.266]    [Pg.267]    [Pg.267]    [Pg.268]    [Pg.269]    [Pg.270]    [Pg.271]    [Pg.404]    [Pg.61]    [Pg.796]    [Pg.141]    [Pg.303]    [Pg.796]    [Pg.392]    [Pg.450]   
See also in sourсe #XX -- [ Pg.21 ]




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