Palladium Phosphino-Iminolate Complexes as
Metalloligands for Coinage Metals: A Versatile,
Ambivalent Behavior<sup>‡</sup>
Nicola Oberbeckmann-Winter
Pierre Braunstein
Richard Welter
10.1021/om050156d.s007
https://acs.figshare.com/articles/dataset/Palladium_Phosphino_Iminolate_Complexes_as_Metalloligands_for_Coinage_Metals_A_Versatile_Ambivalent_Behavior_sup_sup_/3281494
Reactivity studies with the bis-chelated Pd(II) phosphino-iminolate complex [Pd(dmba)(κ<sup>2</sup>-<i>P</i>,<i>O</i>-PPh<sub>2</sub>NC(O)Me)] (<b>2</b>) (dmba = orthometalated dimethylbenzylamine) have shown
that it readily reacts as a metalloligand with electrophilic complexes of the coinage metals,
selectively via the nitrogen atom of the P,O chelate. After examining its reaction with AgOTf
(OTf = SO<sub>3</sub>CF<sub>3</sub>), which afforded the first 1-D coordination polymer containing Ag−Pd bonds,
[{Ag(<b>2</b>)}OTf]<i><sub>n</sub></i> (<b>3</b>·OTf), we have examined and compared its reactions with H<sup>+</sup>, Au(PPh<sub>3</sub>)<sup>+</sup>,
[AuCl(THT)], [Au(THT)]BF<sub>4</sub>, and [Cu(NCMe)<sub>4</sub>]BF<sub>4</sub>. Depending on the nature of the electrophilic metal reagent used, the interaction between the iminolate N atom of <b>2</b> and the
electrophile can be formally described as a dative bond involving its lone pair, which would
formally place the positive charge of the complex more on the coinage metal, or as a more covalent interaction resulting in an increased carbon−oxygen bond order and thus in the pos/baitive charge being more localized on the Pd(II) center. In the former case, the metalloligand
formally behaves as a two-electron, L-type donor, whereas in the latter, as a one-electron,
X-type donor ligand. This ambivalent behavior explains the formation of the heterobimetallic
complexes (<b>6</b>) and ([Au(PPh<sub>3</sub>)(<b>2</b>)]OTf) or
(<b>7</b>·BF<sub>4</sub>), respectively. Double substitution of the d<sup>10</sup> metal center by <b>2</b> afforded the Pd/Au/Pd and Pd/Cu/Pd heterotrinuclear complexes
(<b>8</b>·BF<sub>4</sub>) and (<b>9</b>·BF<sub>4</sub>), respectively. The complexes
<b>2</b>, <b>5</b>·OTf, <b>6</b>, <b>7</b>·BF<sub>4</sub>, <b>8</b>·BF<sub>4</sub>·2CH<sub>2</sub>Cl<sub>2</sub>, and <b>9</b>·BF<sub>4</sub> have been structurally characterized by X-ray
diffraction.
2005-06-20 00:00:00
dative bond
BF 4
electrophilic complexes
Pd
10 metal center
iminolate N atom
complexes 2
NC
CH
coinage metal
nitrogen atom
CF
covalent interaction
Double substitution
coinage metals
heterobimetallic complexes
OTf
electrophilic metal reagent
orthometalated dimethylbenzylamine