title: Formation of double cubanes [Sn(7)(NR)(8)] in the reactions of pyridyl and pyrimidinyl amines with Sn(NMe(2))(2): a synthetic and theoretical study.
abstract: In contrast to the reactions of Sn(NMe(2))(2) with unfunctionalized primary amines (RNH(2)), which yield the simple imido Sn(II) cubanes [SnNR](4), the reactions of 2-pyridyl or 2-pyrimidinyl amines give the mixed-oxidation-state Sn(II)/Sn(IV) double cubanes [Sn(7)(NR)(8)]. In addition to [Sn(7)[2-N(5-Mepy)](8)] x 2thf (1 x 2thf) (py = pyridine) and [Sn(7)[2-N(pm)](8)] x 0.33thf (2 x 0.33thf) (pm = pyrimidine), which were communicated previously, the syntheses and structures of the new complexes [Sn(7)[2-N(4-Mepm)](8)] x 2thf (3 x 2thf), [Sn(7)[2-N(4,6-Me(2)pm)](8)] x 4thf (4 x 4thf), [Sn(7)[2-N(4-Me-6-MeO-pm)](8)] (5), and [Sn(7)[2-N(4-MeO-6-MeO-pm)](8)] (6) are reported. Model DFT calculations on the reactions of Sn(NMe(2))(2) with 2-pmNH(2) or PhNH(2), producing the cubanes [Sn[2-N(pm)]](4) and [SnNPh](4) (respectively), and the corresponding double cubanes [Sn(7)[2-N(pm)](8)] and [Sn(7)(NPh)(8)], show that the presence of intramolecular Sn...N bonding which spans the cubane halves of the complexes is crucial to the formation of the double-cubane structure.
authors.affiliation: Department of Pure and Applied Chemistry, University of Strathclyde, 195 Cathedral Street, Glasgow G1 1XL, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Armstrong
authors.forename: Francesca
authors.initials: F
authors.lastname: Benevelli
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Bond
authors.forename: Neil
authors.initials: N
authors.lastname: Feeder
authors.forename: Eilis A
authors.initials: EA
authors.lastname: Harron
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Hopkins
authors.forename: Mary
authors.initials: M
authors.lastname: McPartlin
authors.forename: David
authors.initials: D
authors.lastname: Moncrieff
authors.forename: David
authors.initials: D
authors.lastname: Sáez
authors.forename: Elsje A
authors.initials: EA
authors.lastname: Quadrelli
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Woods
authors.forename: Dominic S
authors.initials: DS
authors.lastname: Wright