[n.1.1]-(2,6)-Pyridinophanes:  A New Ligand Type Imposing Unusual Metal Coordination Geometries

Abstract

A series of new ligands with three pyridines linked into a macrocycle by various CH(2), CMe(2), and CH(2)CH(2) groups at all sites ortho to the pyridine nitrogen have been synthesized and attached to PdCl(2) or PtMe(2). The ligands bind to them through only two nitrogens, and the third pyridine is constrained in close proximity to the planar complex with a filled d(z)2 orbital. Rapid reversible migration of PdCl(2) or PtMe(2) to the unused pyridine nitrogen is observed at 20 degrees C in the case of the CH(2)-bridged macrocycle and does not occur in the case of the CMe(2)-bridged analogue, and the mechanism of this fluxionality has been established by NMR and computational techniques.

A tripyridylthioether macrocycle: (14,17-dithia-22,23,24-triazatetracyclo[16.3.1.13,7.19,13]tetracosa-1(22),3,5,7(24),9,11,13(23),18,20-nonaene-2,8-dione

“…Known 1-1-1 structures are DUPLUV (Newkome et al, 1986), FICRIT (Suzuki et al, 2005), JEZXUH, JEZYES, JEZYIW, JEZYOC and JEZYUI (Newkome et al, 1990), and TPYDTS10 (Groth, 1973). Only one 1-1-2 structure is known, HUTJEL (Vedernikov et al, 2002), and the only known 1-1-4 structure is the title compound, (II).…”

Angular Ligand Constraint Yields an Improved Olefin Aziridination Catalyst.

“…18 Major component of a mixture resulting from aziridination of cis-2-butene. 1 trans-2,3-Dimethyl-N-tosylaziridine. 18 Minor component of a mixture resulting from aziridination of cis-2-butene.…”

Basicity of Some Pyridinophanes in Gas Phase and Acetonitrile – a DFT Study

“…The aim of the present paper is to provide evidence that [1.1.1]‐(2,6)‐pyridinophane as well as its derivatives addressed above exhibit strong basicity amplified by dressing with electron‐releasing groups in para position of the pyridine rings. It should be stressed that [2.1.1]‐(2,6)‐pyridinophane ( 8 ) has already been synthesized, which is not true for molecule 6 and 7 .…”