cis-Diammineplatinum(IV) complexes of uracil through chlorine treatment of a platinum(II) complex: oxidative addition to the metal and modification (chlorine substitution, hypochlorous acid addition) of the nucleobase

Abstract

Durch Zugabe von frisch dargestelltem Cl, zu einer Lösung des Pt(II)‐Komplexes (I) in Wasser wurde nach Konzentrierung der Lösung bis zu einem pH von 2.3 nach Eindampfen der Pt(IV)‐Komplex (IIa) isoliert.

Oxidative Addition of the Dithiobis(formamidinium) Cation to Platinum(II) Chloro Am(m)ine Compounds: Studies on Structure, Spectroscopic Properties, Reactivity, and Cytotoxicity of a New Class of Platinum(IV) Complexes ExhibitingS-Thiourea Coordination

“…The 1 H NMR spectrum of cis- [PtCl 4 (NH 3 )L] ( 2 ) in DMF- d 7 was found to be similar to that recorded of the structurally related cationic complex fac -[PtCl 3 (NH 3 ) 2 L]Cl·0.5MeOH ( 6 ) in MeOH- d 4 . In addition to a sharp singlet for the methyl protons of tmtu at 3.37 ppm the ammine protons in 2 are observed as a seven-line pattern (1:4:2:4:2:4:1) centered at 5.95 ppm due to heteronuclear couplings ( 1 J ( 14 N− 1 H) ≈ 2 J ( 195 Pt- 1 H) ≈ 50 Hz), characteristic for ammine complexes of Pt(IV) …”

“…12 In addition to a sharp singlet for the methyl protons of tmtu at 3.37 ppm the ammine protons in 2 are observed as a seven-line pattern (1:4:2:4:2:4: 1) centered at 5.95 ppm due to heteronuclear couplings ( 1 J( 14 N-1 H) ≈ 2 J( 195 Pt-1 H) ≈ 50 Hz), characteristic for ammine complexes of Pt(IV). 29 The ethylene groups of the dien ligand in 4 give rise to complicated multiplets centered at 2.85 ppm and between 3.30 and 3.70 ppm (Figure 2). The observed separation of the highfield part of this ABCD system (2H, 3 J( 195 Pt-1 H) ) 24 Hz) from the low-field part (6H) by ca.…”

Binuclear Platinum(II) Triazolopyrimidine Bridged Complexes. Preparation, Crystal Structure, NMR Spectroscopy, and ab Initio MO Investigation on the Bonding Nature of the Pt(II)···Pt(II) Interaction in the Model Compound {Pt2[NHCHN(C(CH2)(CH3))]4}

“…Several compounds of this type have been characterized, with the M−M separation being in the same range as that found for 1 : for example, for (d 7 −d 7 ) K 2 [Pt 2 Cl 2 (diphosphite) 4 ] (BO = 1, d Pt - Pt = 2.695 (1) Å) and for other platinum species with BO ≠ 0, cis- {[(NH 3 ) 2 Pt(1−methylthyminato) 2 PtCl 2 ] 2 Cl}[PtCl 6 ]·6H 2 O, (BO = 0.75, d Pt - Pt = 2.699 (1) Å),9d [Pt 4 (NH 3 ) 8 (α-pyrrolidinato) 4 ](NO 3 ) 6 ·3H 2 O (BO = 0.5, d Pt - Pt = 2.702, 2.709 Å), [Pt 4 (NH 3 ) 8 (α-pyrrolidinato) 4 ](NO 3 ) 5.48 ·3H 2 O (BO = 0.37, d Pt - Pt = 2.765, 2.739, 2.740 Å),9c and [Pt 4 (NH 3 ) 8 (α-pyridonato) 4 ](NO 3 ) 5 (BO = 0.25, d Pt - Pt = 2.779, 2.885 Å) 9a. Nevertheless, our attempts to oxidize 1 with different oxidizing agents such as Ce 4+ /H + ,1b S 2 O 7 2- , HNO 3 /O 2 ,9e H 2 O 2 /H + , Cl 2 /H 2 O in aqueous solution or with NOBF 4 in nonaqueous solvents (DMF and CH 3 CN at −20 °C) were unsuccessful. The low solubility of 1 in aqueous media cannot be rendered as an explanation of this behavior, since, in DMF (in which 1 is soluble), it is also inert.…”

Synthesis, crystal structure and molecular orbital investigation of the first platinum complex of piroxicam

“…molecular orbitals (decreasing energies) for the model molecule trans-[PtC1,(H,SO){NC5H,(NHCOH)-2)] [only those with some N( 16) and Pt character are reported].-15 18. …”