| The chemistry of the tungsten-benzylidyne moiety has been investigated both for understanding its electronic properties and for its use in materials. Herein are reported the synthesis and photophysical characteristics of two types of tungsten-alkylidyne dyads: tungsten-alkylidyne/tungsten-alkylidyne dyads of the type Cl(dppe)2W(≡CC6H4-4-C≡C–{lcub}W(≡CR)(dmpe) 2{rcub}) (R = tert-butyl (6a), phenyl ( 6b)), and the tungsten-alkylidyne/zinc porphyrin dyad Cl(dppe) 2W(≡CC6H4-4-C≡C–{lcub}4′ –(TPP)Zn{rcub}) (11). The electronic properties of the dmpe and dppe ligands present in the tungsten-alkylidyne/tungsten-alkylidyne dyads 6a and 6b alter the electronic and redox properties of the respective metal centers, making it possible to independently address each tungsten-alkylidyne center both optically and electronically. Furthermore, through the synthetic protocol developed for this complex there now exists a route to systems that can be extended both at the tungsten and carbon atoms of the W≡C bond that would allow incorporation of multiple, tunable metal centers. The tungsten-alkylidyne/zinc porphyrin dyad 11 has a well defined structure due to make this system well suited for studying electron transfer through conjugated organometallic wires. Lastly, the syntheses, structures, and photophysical properties of salts of the anionic tungsten-benzylidyne complex [W(≡CPh)(OBut)4] −(1−) with several sodium counterions (Na +, [Na(15-crown-5)]+, [Na(crypt-2,2,2)]+) is reported. Complexes of type the [W(≡CR)(OR′) 4]−, with monodentate alkoxide ligands, are potentially advantageous for the purpose of studying excited-state energies and properties compared to calixarene derivatives because the electronic properties of these ligands should be more broadly tunable. We have discovered that the 1− ion is strongly luminescent in both fluid solution and the solid state at room temperature, and that its structure and photophysical properties are significantly dependent on the nature of the counterion. Although the present data do not allow the two plausible candidates for the emissive state, 3[π(W≡CPh)]1[d xy]1 and 3[π(W≡CPh)] 1[π*(W≡CPh)], to be distinguished, both should be amenable to tuning through counterion and alkylidyne and alkoxide R group variation. Preliminary investigations of the related ions [W(≡CBu t)(OBut)4] − and [{lcub}p-But-calix[4]–(O) 4{rcub}W(≡CR)]− indicate that they are strongly luminescent as well. |
