Azo Complexes
of Osmium(II): Preparation and Reactivity of Organic Azide and Hydrazine
Derivatives
Gabriele Albertin
Stefano Antoniutti
Laura Bonaldo
Alessandra Botter
Jesús Castro
10.1021/ic302483e.s002
https://acs.figshare.com/articles/journal_contribution/Azo_Complexes_of_Osmium_II_Preparation_and_Reactivity_of_Organic_Azide_and_Hydrazine_Derivatives/2433268
Mixed-ligand
hydride complexes OsHCl(CO)(PPh<sub>3</sub>)<sub>2</sub>L (<b>2</b>) [L = P(OMe)<sub>3</sub>, P(OEt)<sub>3</sub>] were prepared by allowing
OsHCl(CO)(PPh<sub>3</sub>)<sub>3</sub> (<b>1</b>) to react with
an excess of phosphite P(OR)<sub>3</sub> in refluxing toluene. Dichloro
compounds OsCl<sub>2</sub>(CO)(PPh<sub>3</sub>)<sub>2</sub>L (<b>3</b>,<b> 4</b>) were also prepared by reacting <b>1</b>, <b>2</b> with HCl. Treatment of hydrides OsHCl(CO)(PPh<sub>3</sub>)<sub>2</sub>L (<b>2</b>), first with triflic acid and
then with an excess of RN<sub>3</sub> afforded organic azide complexes
[OsCl(η<sup>1</sup>-N<sub>3</sub>R)(CO)(PPh<sub>3</sub>)<sub>2</sub>L]BPh<sub>4</sub> (<b>5</b>–<b>7</b>) [R
= 4-CH<sub>3</sub>C<sub>6</sub>H<sub>4</sub>CH<sub>2</sub>, C<sub>6</sub>H<sub>5</sub>CH<sub>2</sub>, C<sub>6</sub>H<sub>5</sub>; L
= P(OEt)<sub>3</sub>]. Benzylazide complexes react in CH<sub>2</sub>Cl<sub>2</sub>/ethanol solution, leading to the imine derivative
[OsCl(CO){η<sup>1</sup>-NHC(H)C<sub>6</sub>H<sub>4</sub>-4-CH<sub>3</sub>}(PPh<sub>3</sub>)<sub>2</sub>{P(OEt)<sub>3</sub>}]BPh<sub>4</sub> (<b>8b</b>). Hydrazine complexes [OsCl(CO)(RNHNH<sub>2</sub>)(PPh<sub>3</sub>)<sub>2</sub>L]BPh<sub>4</sub> (<b>9</b>–<b>11</b>) [R = H, CH<sub>3</sub>, C<sub>6</sub>H<sub>5</sub>; L = P(OMe)<sub>3</sub>, P(OEt)<sub>3</sub>] were prepared
by allowing hydride species OsHCl(CO)(PPh<sub>3</sub>)<sub>2</sub>L (<b>2</b>) to react first with triflic acid and then with
an excess of hydrazine. Aryldiazene derivatives [OsCl(CO)(ArNNH)(PPh<sub>3</sub>)<sub>2</sub>L]BPh<sub>4</sub> (<b>12</b>,<b> 13</b>) were also prepared following two different methods: (i) by oxidizing
arylhydrazine [OsCl(C<sub>6</sub>H<sub>5</sub>NHNH<sub>2</sub>)(CO)(PPh<sub>3</sub>)<sub>2</sub>L]BPh<sub>4</sub> (<b>11</b>) with Pb(OAc)<sub>4</sub> in CH<sub>2</sub>Cl<sub>2</sub> at −30 °C; (ii)
by allowing hydride species OsHCl(CO)(PPh<sub>3</sub>)<sub>2</sub>L (<b>2</b>) to react with aryldiazonium cations ArN<sub>2</sub><sup>+</sup> (Ar = C<sub>6</sub>H<sub>5</sub>, 4-CH<sub>3</sub>C<sub>6</sub>H<sub>4</sub>) in CH<sub>2</sub>Cl<sub>2</sub>. The complexes
were characterized spectroscopically and by X-ray crystal structure
determination of OsHCl(CO)(PPh<sub>3</sub>)<sub>2</sub>[P(OEt)<sub>3</sub>] (<b>2b</b>) and [OsCl{η<sup>1</sup>-NHC(H)C<sub>6</sub>H<sub>4</sub>-4-CH<sub>3</sub>}(CO)(PPh<sub>3</sub>)<sub>2</sub>{P(OEt)<sub>3</sub>}]BPh<sub>4</sub> (<b>8b</b>).
2013-03-18 00:00:00
hydride
RN
CH 2Cl solution
3C
OsCl
CH 2Cl
OsHCl
triflic acid
6H
complex