125656-60-2Relevant academic research and scientific papers
Substitution Reactions toward 2-Nitrobenzyl Pseudohalides. The Crystal Structure of 2-Nitrobenzyl Tellurocyanate
Grung, Knut Eric,Roemming, Christian,Songstad, Jon
, p. 518 - 526 (2007/10/02)
The reactions between 2-nitrobenzyl pseudohalides, 2-NO2-PhCH2XCN, and pseudohalide ions, NCX- (X = S, Se or Te) have been studied kinetically in acetonitrile at 25.0 deg C.The reactions proceed through nucleophilic attack at the methylene carbon atom, forming exclusively the exchange products.The average nucleophilicity order, NCTe- >> NCSe- > NCS-, and the average leaving group order, NCTe- >/= NCSe- >/= NCS-, lead to a carbon basicity order NCTe- > NCSe- >/= NCS-, which is confirmed with equilibrium studies.A crystal structure determination of 2-nitrobenzyl tellurocyanate at ca. 135 deg C has revealed that the TeCN group is syn-clinal (gauche) to the C(CH2)-C(Ar) bond with a torsion angle of -48.5(5) deg.The TeCC plane forms an angle of 103.4(5) deg with the phenyl ring plane.In this conformation the steric influence of the 2-NO2 group in substitution reactions at the methylene carbon atom will be negligible except for bulky nucleophiles.The tellurium atom forms two fairly strong intermolecular bonds to nitrogen atoms from neighbouring tellurocyanate groups, viz. 2.889(6) Angstroem trans to the cyano group and 3.382(6) Angstroem trans to the methylene group.In the crystalline state the compound may be considered both as a tellurium(II) complex and as an organic pseudohalide.No intermolecular tellurium-oxygen contacts could be observed.
