1241386-97-9Relevant academic research and scientific papers
Sterically crowded peri-substituted naphthalene phosphines and their P v derivatives
Knight, Fergus R.,Fuller, Amy L.,Buehl, Michael,Slawin, Alexandra M. Z.,Woollins, J. Derek
experimental part, p. 7617 - 7634 (2010/08/20)
Three sterically crowded pen-substituted naphthalene phosphines, Nap[PPh2][ER] (Nap = naphthalene-l, 8-diyl; ER = SEt, SPh, SePh) 1-3, which contain phosphorus and chalcogen functional groups at the peri positions have been prepared. Each phosphine reacts to form a complete series of P v chalcogenides Nap[P(E')(Ph2)(ER)] (E' = O, S, Se). The novel compounds were fully characterised by using X-ray crystallography and multinuclear NMR spectroscopy, IR spectroscopy and MS. X-ray data for 1, 2, n O, nS, nSe (n = l-3) are compared. Eleven molecular structures have been analysed by naphthalene ring torsions, pen-atom displacement, splay angle magnitude, X-E interactions, aromatic ring orientations and quasi-linear arrangements. An increase in the congestion of the peri region following the introduction of heavy chalcogen atoms is accompanied by a general increase in naphthalene distortion. P-E distances increase for molecules that contain bulkier atoms at the peri positions and also when larger chalcogen atoms are bound to phosphorus. The chalcogenides adopt similar conformations that contain a quasi-linear E-P-C fragment, except for 30, which displays a twist-axial-twist conformation resulting in the formation of a linear O-Se-C alignment. Ab initio MO calculations performed on 2O, 3O, 3S and 3Se reveal Wiberg bond index values of 0.02 to 0.04, which indicates only minor non-bonded interactions; however, calculations on radical cations of 30, 3 S and 3Se reveal increased values (0.140.19).
