Methyl-, acetyl- and allyl-palladium and -platinum complexes containing novel terdentate PNS and NN'S ligands

Abstract

A Methyl-, Acetyl-and Allyl-palladium and -Platinum Complexes Containing Novel Terdentate PNS and NN'S Ligands Ankersmit, H.A.; Veldman, N.; Spek, A.L.; Vrieze, K.; van Koten, G. Published in:Inorganica Chimica Acta DOI:10.1016/S0020-1693(96) Link to publication Citation for published version (APA):Ankersmit, H. A., Veldman, N., Spek, A. L., Vrieze, K., & van Koten, G. (1996). A Methyl-, Acetyl-and Allylpalladium and -Platinum Complexes Containing Novel Terdentate PNS and NN'S Ligands. Inorganica Chimica Acta, 252, 339-354. DOI: 10.1016/S0020-1693(96)05333-9 General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Palladium and platinum compounds of the composition [MX(L) ]X and [M(Me)(L)]X (M =Pd, Pt; X=C1, Br, I, O3SCF3) howe boi~n prepared from the appropriate starting materials and the new ligands (L = N-[2-(diphenylphosphino)benzylidene]-L-methioniool (PNS-I), N-[ 2-(diphenylphosphino) benzylidene l-3-propylethylsuifide (PNS-2),N-{N-[ 2-(diphenylphosphino)benzylidene l-D//-,-methio-nyll-tertbutylamine (PNS-3),N-{N-[2-(pyridine)methylidene]-DIL-methionyl}-tert-butylamine (NN'S)). The single crystal X-ray deterrnination of [PtI(PNS-3)]I (3cz) (triclinic, space group PI (No.2) with a= 10.5298(9), b= 11.5584(8), c= 14.545(2) A, a=T/.368(8), /3=84.453(9), y=79.720(7) °, V= 1696.5(3) A3, Z=2, RI =0.0456, wR'2 =0.1195) showed terdentate coordination of the trifuoctional PNS-3 ligand with a six-memhered PN containing metallacycle and a six-membered NS containing metallacycle which is in a chair conformation. The square planar geometry is completed with an iodide atom, while the second iodide atom is non-coordinating. The methylpalladium and -platinum complexes may occur in solution in various isomeric forms, as an equilibrium has been observed between the ionic [ M (Me) (r/3-PNS) ] X and the neutral [ MX(Me) (,/2-PNS) ]. The ~-PNS bonded complex may occur in two conformations, i.e. with the six-membered NS containing part of the ligand in either the chair or boat form. The methyl-palladium and-platinur ~ complexes reactedslowly with CO to form the con'esponding acetyl complexes, with insertion rates which increased in the order CI < Brl < O3SCF 3-and PNS-I < PNS-2 < PNS-3 < NN'S. Complexes [ Pd (r/3-allyl) (PNS-3) ] X (X = Ci, O3SCF a ) with 2-methylallyl and l,l,2-trimeth...

Insertion Reactions into Palladium–Carbon Bonds of Complexes Containing Terdentate Nitrogen Ligands; Experimental and Ab initio MO Studies

“…In this series ligands 3 and 4 can be considered as rigid analogs of 5 and tpy (6). , similar to what is reported for methylpalladium complexes containing bidentate N-N, [11] [12] N-S [48] [ 49] , P-N [10] , P-P [8] , and terdentate N-N-N [31] [32] , P-N-N [50] , P-N-S [51] , and N-N-S [51] ligands. Analogously to [Pd(Me)(6)]Cl (6a) [32] , complexes 2aϪ5a were obtained as yellow, air-stable solids, which are only moderately soluble in polar solvents such as methanol, ethanol, and water.…”

Methyl-, acetyl- and allyl-palladium and -piatinum complexes containing the novel chiral phosphorus-imine 2-(diphenylphosphino)-benzylidene-S( − )-α-methyl-benzylamine ligand

“…Since the structural and dynamic features of ~-allyl palladium complexes containing chiral NS [34] and PN ligands are also of interest, it was decided to wepare complexes [Pd(~-allyl)(PN)]X (X--CI, OTf) by different mutes (see Sections 2 and 3).…”

“…Since these insertions were found to proceed very slowly (after ~wo weeks only 60% of 7a was converted to 13a) and since we are interested in the structural features of allylpalladium complexes with the chiral PN ligand in comparison with the N--S complexes [34], we decided to prepare The downfield 31p{ tH} NMR resonance shifts (30 < A 8 31p{tH} <40 ppm) and the upfield shift of the IH imine proton ( 0.01 < A 8 ~H < 0.73 ppm) of the PN ligand observed for almost all allylpalladium complexes, when compared to those values found in the free ligand, indicate a chelate bonded ligand in solution, which is corroborated by condtmtivity experiments in CH3OH (Section 2). The observation that the complexes with a chloride counter-ion are non-conducting in CH2CI 2 but conducting in CH3OH is in accordance with the results obtained by ,l.kermark and co-workers on similar complexes [ 35 ], and is due to the formation of contact ion-pairs in CH2C!…”

Solvent Effects on Nitrogen Chemical Shifts

“…For the tridentate S-N-N Pd II complexes 206, 207 (Fig. 28), the pyridinyl nitrogen donor of the complex having Cl À as counterion was significantly deshielded as compared to that having triflate in chloroform-d (δ 15N : À139.8 ppm (Cl À , 206) vs. À158.0 ppm (OTf À , 207)) [142], thus, resulting in 18.2 ppm smaller jΔ 15N coord j for the complex having Cl À than for that having OTf À as counterion. This indicates tight coordination of Cl À whereas no or only weak coordination of OTf À .…”

“…28), comprising OTf À (215), BF 4 À (216), and PF 6 À (217) as counterions, were studied as N-heterocyclic carbene (trzNHC) precursors for [141]. c δ 15N lig for N-(N-(2-pyridyl)methylidene)methionyl-tert-butylamine in CDCl 3 [142]. d δ 15N lig for 2,6-bis(3,4-dimethyl-5-phenyl-1,3-oxazolodin-2-yl)pyridine in CD 2 Cl 2 [143].…”