Linkage isomerism in square-planar complexes of platinum and palladium with histidine and derivatives

Modulation of the chemical and biological properties of trans platinum complexes: monofunctional platinum complexes containing one nucleobase as potential antiviral chemotypes

“…The only other peak that produced an observable shift was the cytosine CH 3 group (d mono = 3.42; d ternary = 3.43 ppm). These results are in accordance with those from preparative studies on 2+ where only very low yields of the mixed amino-acid/nucleobase product were obtained after prolonged reaction [25]. Thus, histidine binding to compounds of general formula [PtCl(nucleobase)(amine) 2 ] is unlikely to be competitive with sulfur by kinetic preference and the reactions were not studied further.…”

“…Platination by N-AcHis in species such as [Pt(dien)(H 2 O)] 2+ and cis/trans- 2+ produces linkage isomers since, at pH 7, both the carboxylate group and the imidazole ring N1 are deprotonated [25]. The 1 H NMR chemical shift of H(2) can move as much as 0.5±1.0 ppm upon platination of the ring nitrogen, and is a sensitive indicator of reaction.…”

Interaction of cisplatin with methionine- and histidine-containing peptides: competition between backbone binding, macrochelation and peptide cleavage

“…8±10 Hz. Square-planar N 4 , N 3 S, and N 2 S 2 coordination spheres can be distinguished through their typical 195 Pt shifts in the respective d ranges ±2650 to ±2900 [20], ±3050 to ±3200, and ±3600 to ±3700 [6].…”

Synthesis, Characterization, and cis–trans Isomerization Studies of cis‐[PdCl2{Ph2P(CH2CH2O)3CH2CH2PPh2‐P,P′}] and trans‐[PtCl2{Ph2P(CH2CH2O)3CH2CH2PPh2‐P,P′}] Metallacrown Ethers

“…[41] were prepared using literature procedures. 2 Cl 2 in 400 mL of dichloromethane, and the resulting solution was stirred at ambient temperature for 20 h. Then, the solution was reduced in volume to 10 mL, and the concentrate was poured into 500 mL of hexanes. The pale yellow precipitate was collected by filtration, washed with hexanes (3 ϫ 30 mL) and dried in vacuo (0.02 Torr at 298 K) for 48 …”

“…We have previously demonstrated that the reaction of Pd(PhCN) 2 mono-mers (n = 1) and cyclic oligomers (n Ͼ 1). [38,40] In contrast, when this reaction is run in a 2:1 acetonitrile/THF mixture, the kinetic product cis-[PdCl 2 {Ph 2 P(CH 2 CH 2 O) 3 CH 2 CH 2 -PPh 2 -P,PЈ}] (cis-1) precipitates from the reaction mixture.…”