1. Spontaneous N2-diboranylation of [W(N2)2(dppe)2] with B2Br4(SMe2)2
Rüdiger Bertermann, Lisa C Haufe, Merle Arrowsmith, Holger Braunschweig, Maximilian Dietz, Annalena Gärtner Dalton Trans . 2022 Aug 30;51(34):12786-12790. doi: 10.1039/d2dt02135h.
The 1,3-bromoboration of [W(N2)2(dppe)2] (dppe = 1,2-bis(diphenylphosphino)ethane) with B2Br4(SMe2)2in the presence of various Lewis bases L yields diboranyldiazenido complexes, with L coordinating either at the terminal or internal boron atom. The 2 : 1 reaction of [W(N2)2(dppe)2] and B2Br4(SMe2)2yields a 1,2-bis(diazenido)diborane-bridged ditungsten complex with a fully planar π-conjugated BrWN2B2Br2N2WBr core.
2. Substitution reactions of [Ru(dppe)(CO)(H(2)O)(3)][OTf](2)
Mary F Mahon, Matthew D Hargreaves, Michael K Whittlesey Inorg Chem . 2002 Jun 17;41(12):3137-45. doi: 10.1021/ic020029z.
The labile nature of the coordinated water ligands in the organometallic aqua complex [Ru(dppe)(CO)(H(2)O)(3)][OTf](2) (1) (dppe = Ph(2)PCH(2)CH(2)PPh(2); OTf = OSO(2)CF(3)) has been investigated through substitution reactions with a range of incoming ligands. Dissolution of 1 in acetonitrile or dimethyl sulfoxide results in the facile displacement of all three waters to give [Ru(dppe)(CO)(CH(3)CN)(3)][OTf](2) (2) and [Ru(dppe)(CO)(DMSO)(3)][OTf](2) (3), respectively. Similarly, 1 reacts with Me(3)CNC to afford [Ru(dppe)(CO)(CNCMe(3))(3)][OTf](2) (4). Addition of 1 equiv of 2,2'-bipyridyl (bpy) or 4,4'-dimethyl-2,2'-bipyridyl (Me(2)bpy) to acetone/water solutions of 1 initially yields [Ru(dppe)(CO)(H(2)O)(bpy)][OTf](2) (5a) and [Ru(dppe)(CO)(H(2)O)(Me(2)bpy)][OTf](2) (6a), in which the coordinated water lies trans to CO. Compounds 5a and 6a rapidly rearrange to isomeric species (5b, 6b) in which the ligated water is trans to dppe. Further reactivity has been demonstrated for 6b, which, upon dissolution in CDCl(3), loses water and coordinates a triflate anion to afford [Ru(dppe)(CO)(OTf)(Me(2)bpy)][OTf] (7). Reaction of 1 with CH(3)CH(2)CH(2)SH gives the dinuclear bridging thiolate complex [[(dppe)Ru(CO)](2)(mu-SCH(2)CH(2)CH(3))(3)][OTf] (8). The reaction of 1 with CO in acetone/water is slow and yields the cationic hydride complex [Ru(dppe)(CO)(3)H][OTf] (9) via a water gas shift reaction. Moreover, the same mechanism can also be used to account for the previously reported synthesis of 1 upon reaction of Ru(dppe)(CO)(2)(OTf)(2) with water (Organometallics 1999, 18, 4068).
3. High photoluminescence from self-assembled Ag2Cl2(dppe)2 clusters through metallophilic interactions
Taeghwan Hyeon, Megalamane S Bootharaju, Guocheng Deng, Hogeun Chang, Sanghwa Lee, Woonhyuk Baek J Chem Phys . 2021 Jul 7;155(1):014307. doi: 10.1063/5.0057356.
Ligand protected metal nanoclusters (NCs) are an emerging class of functional materials with intriguing photophysical and chemical properties. The size and molecular structure play an important role in endowing NCs with characteristic optical and electronic properties. Modulation of these properties through the chemical reactivity of NCs is largely unexplored. Here, we report on the synthesis of self-assembled Ag2Cl2(dppe)2clusters through the ligand-exchange-induced transformation of [Pt2Ag23Cl7(PPh3)10] NCs [(dppe): 1,2-bis(diphenylphosphino)ethane; (PPh3): triphenylphosphine]. The single crystal x-ray structure reveals that two Ag atoms are bridged by one dppe and two Cl ligands, forming a Ag2Cl2(dppe) cluster, which is subsequently self-assembled through dppe ligands to form [Ag2Cl2(dppe)2]n. Importantly, the Ag2Cl2(dppe)2cluster assembly exhibits high photoluminescence quantum yield: ~18%, which is attributed to the metallophilic interactions and rigidification of the ligand shell. We hope that this work will motivate the exploitation of the chemical reactivity of NCs as a new path to attain cluster assemblies endowed with enhanced photophysical properties.
