Cyclometallated iridium(III) complexes with 2-phenylpyridine [Ir(ppy)2(CNR)Cl] (ppy = (2-phenylpyridinato-C2,N), R = Xyl, Mes), [Ir(ppy)2(CNR)2](OTf) (R = Xyl, Mes), and fac-[Ir(ppy)3] catalyse the cross-linking of polysiloxanes exclusively at temperatures above 100 °C leading to luminescent rubbers.
cis- and trans-Isomers of the platinum(II) nitrile complexes [PtCl2(NCR)2] (R = NMe2, N(C5H10), Ph, CH2Ph) were examined as catalysts for hydrosilylation cross-linking of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated poly(dimethylsiloxane-co-ethylhydrosiloxane) producing high quality silicone rubbers. Among the tested platinum species the cis-complexes are much more active catalysts than their trans-congeners and for all studied platinum complexes cis-[PtCl2(NCCH2Ph)2] exhibits the best catalytic activity (room temperature, c = 1.0 × 10−4 mol/L, τpot-life 60 min, τcuring 6 h). Although cis-[PtCl2(NCCH2Ph)2] is less active than the widely used Karstedt’s catalyst, its application for the cross-linking can be performed not only at room temperature (c = 1.0 × 10−4 mol/L), but also, more efficiently, at 80 °C (c = 1.0 × 10−4–1.0 × 10−5 mol/L) and it prevents adherence of the formed silicone rubbers to equipment. The usage of the cis- and trans-[PtCl2(NCR)2] complexes as the hydrosilylation catalysts do not require any inhibitors and, moreover, the complexes and their mixtures with vinyl- and trimethylsilyl terminated polysiloxanes are shelf-stable in air. Tested catalysts do not form colloid platinum particles after the cross-linking.
C,N-Chelate deprotonated diaminocarbene platinum(II) complexes were synthesized by coupling coordinated isocyanides and azinyl-substituted ureas. The complexes act as catalysts of α,ω-divinylpolydimethylsiloxane and poly(dimethylsiloxane-co-methylhydrosiloxane) hydrosilylation cross-linking. Silicone rubbers obtained with (aminoisoquinoline)-containing complex 3d exhibit temperature-responsive luminescence. Their emission changes irreversibly when heated from 80–100 °C (green radiation) to 120 °C or more (blue radiation).