Tuning Reactivity of Platinum(II) Complexes

(pht, 99%), including sodium perchlorate monohydrate †(NaClO4.H2O, 98%)and
perchloric acid (HClO4, 70%) were purchased from Aldrich and used without further
purification. Silver perchlorate (AgClO4, 99.9%) from Aldrich was stored under nitrogen
and used as supplied. Methanol (Saarchem) was distilled and dried over magnesium
before use. 31 For all preparations of aqueous solutions, ultrapure water (Modulab
Systems) was used.
5.2.2 Synthesis of the Dinuclear Pt(II) chloro-complexes (pzn to pht)
The dinuclear platinum(II) complexes [{cis–PtCl(NH3)2}2–μ–pzn](ClO4)2 (pzn), [{cis–
PtCl(NH3)2}2–μ–pmn](ClO4)2 (pmn), [{cis–PtCl(NH3)2}2–μ–pdn](ClO4)2 (pdn), [{cis–
PtCl(NH3)2}2–μ–qzn]Cl2 (qzn), and [{cis–PtCl(NH3)2}2–μ–pht](ClO4)2 (pht), were
synthesized from the precursor molecule, [{cis–PtCl(NH3)2(DMF)]ClO4, according to a
literature method 32 using AgClO4. The synthetic method is the same as described in
chapter 4 (section 4.2.3).
Their purity was confirmed by micro-elemental analysis, infrared (IR), 1H and 195Pt
NMR. The IR spectra of all the complexes exhibited common characteristic peaks in the
range 326-400 cm -1 (weak) for Pt–Cl and 1090-1100 cm -1 (broad, strong) for Cl–O
(perchlorate counter ion) vibration stretches, respectively.
pzn: Yield: 382.8 mg (0. 474 mmol, 45.5%). 1 H NMR (500.5 MHz, D2O) δ /ppm: 1H: 8.99,
s (4H). 195 Pt NMR (107.5 MHz, D2O): δ/ ppm: -2302.20. IR (KBr, 4000-300 cm -1 ): 3305,
3224, 3107 (N–H stretch); 1658 (C=N, pyrazine group stretch); 1090-1100 (perchlorate
counter ion); 450-490 (Pt–N stretch); 340 (Pt–Cl stretch). Anal. Calcd for
C4H16N6Cl4O8Pt2: H, 2.00; C, 5.94; N, 10.40. Found: H, 2.23; C, 5.45; N, 9.90%.
pmn: Yield: 220.9 mg (0. 273 mmol, 44.3%). 1H NMR (500.5 MHz, D2O) δ/ppm:10.01 (s,
1H); 9.26 (d, 2H); 7.85, (t, 1H). 195 Pt NMR (107.5 MHz, D2O) δ/ ppm: -2320.55. IR (KBr,
Caution! †Metal perchlorate complexes and perchloric acid are potentially explosive. They should be
handled with care, and the complexes should be prepared in small quantities.
5