Diborane(6) and Its Analogues Stabilized by Mono-, Bi-, and Trinuclear Group 7 Templates Combined Experimental and Theoretical Studies

International audienceIrradiation of [Re(CO)] in the presence of BH·thf resulted in the formation of several rhenium diborane(6) species, for example, [{(OC)Re}{Re(CO)}(μ-ηηη-BH)(μ-H)], 1; [{(OC)Re}{Re(CO)}(μ-ηηη-BH)(μ-H)], 2; and [{(OC)Re}(μ-ηη-BH)], 3, comprising diverse coordination modes of the [BH] ligand. Compound 1 contains a tris(bidentate) [BH] unit, whereas 2 consists of an unsymmetrically bound [μ-ηηη-BH] ligand. In contrast, the irradiation of [Mn(CO)] with BH·thf yielded only the Mn analogue of 1, [{(OC)Mn}{Mn(CO)}(μ-ηηη-BH)(μ-H)], 1'. In an attempt to generate the bimetallic Mn-diborane(6), we have carried out the reaction of 1' with PCy under photolytic conditions. The reaction led to the formation of two single base stabilized unsymmetrical diborane(5) species, [{Mn(CO)}{Mn(CO)PCy}(μ-ηη-BH·PCy)(μ-H)], 4, and [{Mn(CO)PCy}(η-BH·PCy)], 5. As [BH] and [BH·PCy] are isoelectronic, the bondings in 4 and 5 are analogous to that of diborane(6) species 1-3. All the new species have been characterized spectroscopically, and their structures were further confirmed by single-crystal X-ray diffraction studies. DFT-type quantum chemical calculations were carried out that provided insight into the bonding interaction of [BH] and [BH·PCy] with the M(CO) fragments

Dual Probe Sensors Using Atomically Precise Noble Metal Clusters

This article adds a new direction to the functional capability of protein-protected atomically precise gold clusters as sensors. Counting on the extensively researched intense luminescence of these clusters and considering the electron donating nature of select amino acids, we introduce a dual probe sensor capable of sensing changes in luminescence and conductivity, utilizing bovine serum albumin-protected atomically precise gold clusters hosted on nanofibers. To this end, we have also developed a hybrid nanofiber with a conducting core with a porous dielectric shell. We show that clusters in combination with nanofibers offer a highly selective and sensitive platform for the detection of trace quantities of trinitrotoluene, both in solution and in the vapor phase. In the solution phase, trinitrotoluene (TNT) can be detected down to 1 ppt at room temperature, whereas in vapor phase, 4.8 × 10⁹ molecules of TNT can be sensed using a 1 mm fiber. Although the development in electrospinning techniques for fabricating nanofibers as sensors is quite substantial, a hybrid fiber with the dual properties of conductivity and luminescence has not been reported yet