Formation of three- and two-electron σ-bonds by removal of lone pair electrons from a diamine

Abstract

8,9,1O,ll-Tetrahydro-7H-7,ll-propanonaphtho- [ 1,8-bc] [ 1,5]diazocine (1) is reversibly oxidised to (2) and(3) ; spectroscopic data for (2) and (3) suggest that simple two-centre 3-and 2-electron a-bonds are formed in the oxidation.THE preparation, solid-state structure, and photoelectron spectrum of (1) have been rep0rted.l Cyclic voltammetry of (1) in MeCN (Pt anode, 0 . 2 ~ Et4NBF4 supporting electrolyte) shows two reversible waves at +0.11 and +0.72 V us. SCE. The second wave is only reversible at scan speeds > 1 V s-l and then only when the special drying technique of Hammerich and Parker2 is used. These oxidation potentials are exceptionally low for a non-conj ugated amine and are similar to those for NNN'N'-tetramethyl-P-phenyl-

Naphthalene 'proton sponges'

“…The oxidation of compound 23 occurs in an analogous way, but more easily. 120 Its radical cation can be conserved unchanged in acetonitrile over a period of many months. The UV spectrum of this radical cation (l max = 480 nm, lg e = 3.1) is very similar to that of compound 23 itself, which has led to a conclusion that the naphthalene fragment of the molecule does not take part in the oxidation.…”

Effects of structure on the ease of electron removal from o-phenylenediamines

“…Unfortunately, 5-Me showed a completely irreversible oxidation peak under all conditions employed (£pox = +0.31, 23 °C, 100 mV/s; Ep°>: = +0.3, -78 °C, 100 mV/s). We believe that this problem is caused by the aromaticity of the deprotonated 2-electron oxidation product, dimethylbenzimidizolium cation 10+.…”

“…(2-10 V/s) 14A 66102-37-2 23 Irrev., £pox = 1.27 (0.2 V/s) -45 Quasirev., E°s 1.18 ± 0.04 (0.5-10 V/s) 14B 66102-38-3 24 Irrev., £pox = 1.26 (0.5 V/s) -48 Irrev., £p°x = 1.40 (2 V/s) 15 7140-45-6 21 Irrev., Epox = 1.10 (0.2 V/s) well behaved waves were observed, appear in Table I. We believe the potentials reported to be accurate to +0.01 V.…”