Facile Synthesis of New, Stable, Palladium-Ethyl Derivatives Containing Nitrogen-Donor Ligands

Palladium Carbene Complexes for Selective Alkene Di- and Oligomerization

“…29 However, catalytic experiments with these modified complexes did not afford any detectable quantities of the insertion products and no resonances were observed that could be tentatively attributed to a Pd-ethyl species.…”

15N NMR coordination shifts in Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with pyridine, 2,2′-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2′-biquinoline, 2,2′:6′, 2′-terpyridine and their alkyl or aryl

“…[15,16] www.interscience.wiley.com/journal/mrc [23] In the same species, the | 15N coord | parameters for nitrogens of the monodentate L ligands (py, 2-phenyl-py, 7,8-benzoquinoline) are again within the range typical for their trans position to N (ca 61-80 ppm). [15,16] An analogous ca 35 ppm difference between py nitrogens trans to N and trans to CH 3 [11,12] and a relatively high structural similarity of this ligand to the earlier mentioned 2-(3 -methyl-5 -pyrazolyl)-py (δ 15N lig = −84.9 ppm [9] ), one can evaluate | 15N coord | as ca 50-60 ppm.…”

“…[15,16] www.interscience.wiley.com/journal/mrc [23] In the same species, the | 15N coord | parameters for nitrogens of the monodentate L ligands (py, 2-phenyl-py, 7,8-benzoquinoline) are again within the range typical for their trans position to N (ca 61-80 ppm). [15,16] An analogous ca 35 ppm difference between py nitrogens trans to N and trans to CH 3 [11,12] and a relatively high structural similarity of this ligand to the earlier mentioned 2-(3 -methyl-5 -pyrazolyl)-py (δ 15N lig = −84.9 ppm [9] ), one can evaluate | 15N coord | as ca 50-60 ppm. The influence of Cl atoms in the trans position is generally slightly smaller than that caused by N. This is evident for some dichloride complexes described by Pazderski et [7,14,19] Another species fitting to this scheme is the diazide complex trans-[Pd(py) 2 www.interscience.wiley.com/journal/mrc Axial 4-tert-butyl-py −161.4 [25] −92.6 g 1 J 15N -103Rh = 17.9 Hz Equatorial 4-tert-butyl-py (trans to CH 2 C 6 H 5 )…”

“…The lability effect is evident for [Pd(LL)(LL )R] + cations (LL = phen, 3,4,7,8-tmphen; R = CH 3 , C 2 H 5 ), described by Milani et al, [15,16] [15,16] The diminishing of | 15N coord | parameters upon lability of Pd-N bonds is exemplified also by only formally similar [Pd(phen)(bis(anisylimino)acenapthene)(CH 3 )] + and [Pd(2,9-dmphen )(bis(anisylimino)acenapthene)(CH 3 )] + cations, which were exhibited by Groen et al to differ in their complexation mode. [18] The former species, containing a chelated phen molecule (and monodentately bonded bis(anisylimino)acenapthene) has | 15N coord | of 63.6 ppm, intermediate between the ranges typical for nitrogens trans to N and trans to CH 3 (only one 15 N signal of phen being detected because of the fast exchange of auxiliary ligands, which leads to the equivalency of both chelating N atoms).…”

“…[17] The variability of | 15N coord | parameters with the change of azine ligand is rather limited. Particularly, the introduction of alkyl or aryl side groups into the py, bpy or phen rings has resulted in rather slight | 15N coord | variations, not exceeding 10 ppm : 88.2 ppm for [Pd (4,4 - [15,16] The change of the whole heterocyclic ring system (but with the same type of coordination geometry) has been followed by more noticeable ca [10][11][12][13][14][15][16][17][18][19][20] [7,14] ; however, sometimes this effect can be also negligible: 98.5 ppm for trans-[Pd(isoquin) 2 Cl 2 ] versus 99.5 ppm for trans-[Pd(py) 2 Cl 2 ]. [7,19] The dependence on the electric charge of the complex is usually less than 10 ppm, as exemplified by the | 15N…”