A new cyclometalated derivative, (NBu4)[Pt(bzq)(C6Cl5)2] (2) (bzq = 7,8-benzoquinolate), and three novel polymetallic species containing donor−acceptor Pt→Ag bonds, (NBu4)[{Pt(bzq)(C6F5)2}2Ag] (3) and [{Pt(bzq)(C6X5)2}Ag(PPh3)] (X = F (4), Cl (5)), have been synthesized and characterized by X-ray diffraction methods. 3 is prepared by reaction of (NBu4)[Pt(bzq)(C6F5)2] (1) with AgClO4 in 1:1 or 1:0.5 molar ratio, while 4 and 5 are the results of the reaction of the corresponding (NBu4)[Pt(bzq)(C6X5)2] (X = F (1), Cl (2)) precursors with [Ag(OClO3)(PPh3)] in 1:1 molar ratio. 3 has been found to crystallize in two forms:  monoclinic (3a) and triclinic (3b), which differ not only in the conformation of the basic Pt2Ag anion (anti and planar 3a, staggered and nonplanar 3b), but also in the crystal packing (π···π extended structure 3a, and a stacked dimer 3b) and luminescence at 298 K (orange 3a, green 3b). At 77 K, the orange band (568 nm) of 3a, attributed to a ππ* excimeric emission, is not detected, and both polymorphs exhibit identical green emission (3LC/3MLCT). Spectroscopic study of 4 and 5 (UV−vis and luminescence) was also performed to examine the role of the Pt→Ag donor−acceptor bond. The most significant feature is the blue shift observed in the low-energy UV absorption and the appearance of two, close, distinct, structured emissions with short (487 4; 490 nm 5) and long (502 nm 4, 5) lifetime, but only in the solid state at 77 K.

A novel series of anionic mononuclear terdentate dicyclometalated complexes (NBu4)[Pt(CwedgeNwedgeC)X] (HCwedgeNwedgeCH=2,6-diphenylpyridine) containing acetylide (X=C[triple bond]CR, R=tBu, 1; Ph, 2; Tol, 3; (4-OMe)C6H4, 4) or another anionic ligand (X=CN, 5; S-2Py, 6; CH2COCH3, 7) have been synthesized and fully characterized. The solid-state structures of complexes 1 and 4-6 have also been determined by X-ray diffraction studies, showing, in all the cases, the presence of several types of weak hydrogen interactions, leading to the generation of supramolecular 2D (1) or 3D (4-6) architectures. All the complexes (1-7) are intensely luminescent at low temperature (solid and glassy CH2Cl2), exhibiting concentration dependence in the emissions of the glassy CH2Cl2 matrix.

Ruthenium trisbipyridine C 60 dyads linked via para-phenyleneethynylene units have been prepared. They displayed a rapid energy transfer from Ru to C 60 with a rate that was independent of distance, from 1.1 to 2.3 nm. The results are explained by a hopping mechanism involving a bridge-localized excited-state. In fact, for the longest bridge this state was lower in energy than the Ru-based MLCT state, as evidenced by the spectroscopic data.w Electronic supplementary information (ESI) available: Transient absorption spectra and traces for D 1 -D 3 and R 1 , and a Table with kinetic data from a global fit. See

A new neutral cyclometalated platinum(II) solvate complex [cis-Pt(bzq)(C(6)F(5))(acetone)] (1) has been prepared by easy C-H activation of 7,8-benzo[h]quinoline on the coordination sphere of [cis-Pt(C(6)F(5))(2)(thf)(2)] (thf = tetrahydrofuran). The study of the reaction pathway has led us to the preparation of the bis(Hbzq) product [cis-Pt(C(6)F(5))(2)(Hbzq)(2)] (2) and the benzoquinoline-benzoquinolate derivative [Pt(bzq)(C(6)F(5))(Hbzq)] (3). This latter complex has been characterized by X-ray diffraction, showing the occurrence of π···π intermolecular stacking interactions associated to the deprotonated bzq units. The acetone molecule in [cis-Pt(bzq)(C(6)F(5))(acetone)] can be easily displaced by alkynes, allowing the synthesis of the first reported η(2)-alkyne-cycloplatinate complexes [Pt(bzq)(C(6)F(5))(η(2)-RC≡CR')] (R = H, R' = Ph 4, (t)Bu 5, Fc 6; R = R' = Ph 7), which have been fully characterized spectroscopically and by DFT studies. These alkyne complexes are only moderately stable in solution, and all attempts to obtain crystals suitable for X-ray diffraction were fruitless. Nevertheless, in the case of the ferrocenyl derivative, crystals of complex [Pt(κN:η(2)-bzq-C≡CFc)(C(6)F(5))(μ-κC(α):η(2)-C≡CFc)Pt(bzq)(C(6)F(5))] (8), containing an unusual alkynyl-functionalized benzoquinoline chelate ligand, were systematically obtained. All complexes (except those containing the ferrocenyl fragment) present emissive properties in solution and solid state (77 K), related, in general, with intraligand (bzq) excited states with some mixing (3)MLCT character, as supported by theoretical calculations. In solid state at room temperature, aggregation induced emission (AIE) is observed likely generated by intermolecular π···π stacking, as supporting by DFT calculations on 3(2). Interestingly, both types of excited states ((3)IL/(3)MLCT and AIE) seem to be close in energy in complexes 1 and 3, which show a significant luminescent thermochromism (green 77 K to orange 298 K).