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Ambient-temperature photolysis of the aminoborylene complex [(OC)5CrBN(SiMe3)2] in the presence of a series of trans-bis(alkynyl)platinum(II) precursors of the type trans-[Pt(CCAr)2(PEt3)2] (Ar=Ph, p-C6H4OMe, and p-C6H4CF3) successfully leads to twofold transfer of the borylene moiety [ :BN(SiMe3)2] onto the alkyne functionalities. The alkynyl precursors and resultant bis(borirene)platinum(II) complexes formed are of the type trans-[Pt(B{N(SiMe3)2}CCAr)2(PEt3)2] (Ar=Ph, p-C6H4OMe, and p-C6H4CF3). These species have all been successfully characterized by NMR, IR, and UV/Vis spectroscopy as well as by elemental analysis. Single-crystal X-ray diffraction has verified that these trans-bis(borirene)platinum(II) complexes display coplanarity between the twin three-membered rings across the platinum core in the solid state and stand as the first examples of coplanar conformations of twin borirene systems. These complexes were modeled using density functional theory (DFT), providing information helpful in determining the ability of the transition metal core to interact with each individual borirene ring system and allowing for the observed coplanarity of these rings in the solid state. This proposed transition metal interaction with the twin borirene systems is manifested in the electronic characterization of these borirene species, which display divergent photophysical UV/Vis spectroscopic profiles compared to a previously published mono(borirene)platinum(II) complex. [ABSTRACT FROM AUTHOR]

The reaction of [Pt(PCy3)2] with Br2B-CH(SiMe3)2 resulted in generation of the first alkylideneboryl complex, trans-[Br(Cy3P)2Pt{BCH(SiMe3)}], with concomitant elimination of Me3SiBr. The trans bromide ligand of the alkylideneboryl complex was readily substituted by a methyl group upon treatment with methyllithium, leading to another alkylideneboryl complex, trans-[Me(Cy3P)2Pt{BCH(SiMe3)}]. Various spectrochemical techniques, single-crystal X-ray crystallography, and quantum chemical calculations confirmed the formulation of a double bond between the boron and the carbon atom. The theoretical studies also provided evidence for the stronger trans influence of the alkylideneboryl ligand over iminoboryl and oxoboryl ligands. [ABSTRACT FROM AUTHOR]

We herein report detailed investigations into the interaction of Lewis acidic fluoroboranes, for example BF2Pf (Pf=perfluorophenyl) and BF2ArF (ArF=3,5-bis(trifluoromethyl)phenyl), with Lewis basic platinum complexes such as [Pt(PEt3)3] and [Pt(PCy3)2] (Cy=cyclohexyl). Two presumed Lewis adducts could be identified in solution and corresponding secondary products of these Lewis adducts were characterized in the solid state. Furthermore, the concept of frustrated Lewis pairs (FLP) was applied to the activation of ethene in the system [Pt(BPf3)(CH2CH2)(dcpp)] (dcpp=1,3-bis(dicyclohexylphosphino)propane; Pf=perfluorophenyl). Finally, DFT calculations were performed to determine the interaction between the platinum-centered Lewis bases and the boron-centered Lewis acids. Additionally, several possible mechanisms for the oxidative addition of the boranes BF3, BCl3, and BF2ArF to the model complex [Pt(PMe3)2] are presented. [ABSTRACT FROM AUTHOR]

Studies on the reactivity of the novel bis(phosphine) platinum complex [Pt{P(CH2Cy)3}2] towards haloboranes are presented. The resulting complexes of the general formula trans-[Pt{B( R) R′} X{P(CH2Cy)3}2] were isolated in good to excellent yields (82-91 %) and the molecular structure of trans-[Pt{B(Br)Fc}Br{P(CH2Cy)3}2] is reported. The reactions of 1,4-(Br2B)2C6H4 and 1,3,5-(Br2B)3C6H3 with two and three equivalents of the platinum precursor yield the corresponding di- and trinuclear boryl platinum complexes, respectively. The structural characterization of the first trinuclear triboryl complex 1,3,5- trans-[Pt(BBr)Br{P(CH2Cy)3}2]3C6H3 extends the number of possible structural motifs in boryl platinum chemistry by a noteworthy example and confirms that P(CH2Cy)3 has flexible steric bulk. [ABSTRACT FROM AUTHOR]

Photolysis of an aminoborylene complex in the presence of trans ‐ bis(alkynyl)platinum(II) precursors of the type trans ‐ [Pt(CCAr)2(PEt3)2] leads to a series of bis(σC ‐ borirenyl) complexes of PtII. These complexes display coplanarity of the borirene rings in the solid state, making them the first examples of borirene coplanarity. For more details, see the Full Paper by H. Braunschweig et al. on page 2377 ff. [ABSTRACT FROM AUTHOR]