Angel J. Rueda

Hydrogen-bond mediation of supramolecular aggregation in neutral bis-(C6F5)Pt complexes with aromatic H-bond donating ligands. A synthetic and structural study

Six pentafluorophenylplatinum(II) complexes containing proton acceptor atoms (F) and pyridine-like aromatic ligands able to act as proton donors have been synthesized and characterized, with emphasis on the factors that mediate their supramolecular aggregation in the solid state--hydrogen bonds and pi-pi interactions. The crystal structure analyses of the mononuclear complexes cis-[Pt(C6F5)2(napy)](1), cis-[Pt(C6F5)2(CH2napy)](3), cis-[Pt(C6F5)2(2-ammpy)](5), and cis-[Pt(C6F5)2(2-bipym)](6) reveal the influence of D-HPt and D-HF (D=C, N) hydrogen bonding on the organization of molecules into stacks, which can be further interconnected to generate channels. The prevalence of hydrogen bonding over pi-pi interactions between aromatic rings in establishing the nature of the observed supramolecular aggregation is demonstrated.

RATIONAL SYNTHESIS OF DI-, TRI- AND TETRANUCLEAR COMPOUNDS BY USING THE PT(C6F5)2(C5H4NS)- ANION AS A METALLOLIGAND

Abstract The compound [NBu4][Pt(C6F5)2(C5H4NS-κN,κS)] (1) reacts with the chloro complexes [NBu4]n[Pt(C6F5)2Cl(L)] in the presence of AgClO4, giving rise to the dinuclear derivatives [NBu4]n[Pt2(C6F5)4(C5H4NS)(L)] (n = 1 when L = PPh3 (2) or CO (3); n = 2 when L = C6F5 (4). The reaction of 1 with the neutral species [PtCl2(L-L)] proceeds spontaneously without any auxiliary halide abstractor, giving the trinuclear compounds [Pt(C6F5)2C5H4NS)2Pt(L-L)] (L-L = cod (7), dppm (8). By reaction of 1 with cis-[Pt(C6F5)2OC4H8)2], the tetranuclear compound [NBu4]2[Pt4(C6F5)8(C5H4NS)2] (9) has been obtained. Complex 9 can alternatively be prepared by reaction of 1 with [NBu4]2[Pt2(μCl)2(C6F5)4] in the presence of AgClO4. Crystals of 9 are triclinic, space group P 1 with a = 1123.3(3), b = 1540.1(3), c = 1630.9(4) pm, α = 110.94(2), β = 96.80(2), γ = 94.50(2)°, U = 2.594 nm3and Z = 1. The homotetranuclear anion of 9 provides, to our knowledge, the first example of a new coordination mode of the pyridine-2-thiolato ligand, which is coordinated as a chelate to one of the metal centres, while its S atom bridges two additional metal ions, thus resulting in a μ3-S situation. No evidence for the existence of M-M interaction has been observed. The reaction of 1 with [Ag(ClO4)(PPh3)] gives the highly insoluble, heteropolynuclear species [AgPt(C6F5)2(C5H4NS)(PPh3)]x (5), which can also be obtained by reaction of [NBu4][Pt(C6F5)2(C2H4NS-κS)(PPh3)] with AgClO4. Treatment of 5 with PPh3 produces the solubilisation of the polymer by forming the heterodinuclear derivative [AgPt(C6F5)2(C5H4NS)(PPh3)2] (6). Crystals of 6 are triclinic, of space group P 1 , with a = 1362.0(1), b = 1412.2(1), c = 1499.1(1) pm, α = 104.791(7), β = 90.725(6), γ = 102.720(6)°, U = 2.7122(3) nm3and Z = 2. The Ag(I) ion in 6 is linearly coordinated to the bridging S atom and to one of the P atoms, showing an additional Ag…N interaction.

Synthesis and structural characterization of the luminescent tetranuclear complex [NBu4]2[(C6F5)6(μ-OH)3Pt3HgCl] with Pt–Hg bonds unsupported by covalent bridging ligands

The tetranuclear cluster [NBu 4 ] 2 [(C 6 F 5 ) 6 (μ-OH) 3 Pt 3 HgCl] is obtained by reacting the mononuclear platinum complex [NBu 4 ] 2 [Pt(C 6 F 5 ) 3 Cl] with Hg(NO 3 ) 2 followed by appropriate work-up. The X-ray study reveals that the compound possesses three donor–acceptor Pt→Hg bonds unsupported by any covalent bridges. The crystallographic parameters are: monoclinic, P 2 1 / n with a =11.9770(10), b =26.092(3), c =24.991(2) A, β= 92.900(10)°, D calc =2.009 Mg m −3 for Z =4 and R =0.076 utilizing 13 657 data with F o 2 ≥2 σ ( F o 2 ). The UV–vis spectrum of the solid sample has been studied revealing that the compound is strongly luminescent.