Non-Innocent Base Properties of 3- and 4-Pyridyl-dithia- and Diselenadiazolyl Radicals: The Effect of N -Methylation - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Inorganic Chemistry Année : 2018

Non-Innocent Base Properties of 3- and 4-Pyridyl-dithia- and Diselenadiazolyl Radicals: The Effect of N -Methylation

Résumé

Condensation of persilylated nicotinimideamide and isonicotinimideamide with sulfur monochloride affords double salts of the 3-, 4-pyridyl-substituted 1,2,3,5-dithiadiazolylium DTDA cations of the general formula [3-, 4-pyDTDA][Cl][HCl] in which the pyridyl nitrogen serves as a noninnocent base. Reduction of these salts with triphenylantimony followed by deprotonation of the intermediate-protonated radical affords the free base radicals [3-, 4-pyDTDA], the crystal structures of which, along with those of their diselenadiazolyl analogues [3-, 4-pyDSDA], have been characterized by powder or single-crystal X-ray diffraction. The crystal structures consist of “pancake” π-dimers linked head-to-tail into ribbonlike arrays by η2-S2---N(py) intermolecular secondary bonding interactions. Methylation of the persilylated (iso)nicotinimide-amides prior to condensation with sulfur monochloride leads to N-methylated double chloride salts Me[3-, 4-pyDTDA][Cl]2, which can be converted by metathesis into the corresponding triflates Me[3-, 4-pyDTDA][OTf]2 and then reduced to the N-methylated radical triflates Me[3-, 4-pyDTDA][OTf]. The crystal structures of both the N-methylated double triflate and radical triflate salts have been determined by single-crystal X-ray diffraction. The latter consist of trans-cofacial π-dimers strongly ion-paired with triflate anions. Variable temperature magnetic susceptibility measurements on both the neutral and radical ion dimers indicate that they are diamagnetic over the temperature range 2–300 K.

Domaines

Matériaux

Dates et versions

hal-02178758 , version 1 (10-07-2019)

Identifiants

Citer

Anni Taponen, Joanne Wong, Kristina Lekin, Abdeljalil Assoud, Craig Robertson, et al.. Non-Innocent Base Properties of 3- and 4-Pyridyl-dithia- and Diselenadiazolyl Radicals: The Effect of N -Methylation. Inorganic Chemistry, 2018, 57 (21), pp.13901-13911. ⟨10.1021/acs.inorgchem.8b02416⟩. ⟨hal-02178758⟩

Collections

CNRS INC-CNRS
8 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More