Preparation of platinum(II) complexes with L-serine using KI. X-ray crystal structure, HPLC and 195Pt NMR spectra.
The preparation of platinum(II) complexes containing L-serine using K(2)[PtCl(4)] and KI as raw materials was undertaken. The cis-trans isomer ratio of the complexes in the reaction mixture differed significantly depending on whether KI was present or absent in the reaction mixture. One of the two [Pt(L-ser-N,O)(2)] complexes (L-ser=L-serinate anion) prepared using KI crystallizes in the monoclinic space group P2(1)2(1)2(1) with unit cell dimensions a=8.710(2) A, b=9.773(3) A, c=11.355(3) A, Z=4. The crystal data revealed that this complex has a cis configuration. The other [Pt(L-ser-N,O)(2)] complex also crystallizes in the monoclinic space group P2(1)2(1)2(1) with unit cell dimensions a=7.0190(9) A, b=7.7445(6) A, c=20.946(2) A, Z=4. The crystal data revealed that this complex has a trans configuration. The 195Pt NMR chemical shifts of trans-[Pt(L-ser-N,O)(2)] and cis-[Pt(L-ser-N,O)(2)] complexes are -1632 and -1832 ppm, respectively. 195Pt NMR and HPLC measurements were conducted to monitor the reactions of the two [Pt(L-ser-N,O)(2)] complexes with HCl. Both 195Pt NMR and HPLC showed that the reactivities of cis- and trans-[Pt(L-ser-N,O)(2)] toward HCl are different: coordinated carboxyl oxygen atoms of trans-[Pt(L-ser-N,O)(2)] were detached faster than those for cis-[Pt(L-ser-N,O)(2)].
D002712:Chlorides / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D006851:Hydrochloric Acid / Q000737:chemistry; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000138:chemical synthesis*; D010984:Platinum / Q000737:chemistry*; D017671:Platinum Compounds / Q000737:chemistry; D011193:Potassium Iodide / Q000737:chemistry; D012694:Serine / Q000031:analogs & derivatives*
D002712:Chlorides; D009944:Organoplatinum Compounds; D017671:Platinum Compounds; C036919:tetrachloroplatinate; D011193:Potassium Iodide; D012694:Serine; D010984:Platinum; D006851:Hydrochloric Acid