the determination of monolayer structure by infrared spectroscopy: CO2 on NaCl(100)

Infrared spectra of a ¹²C¹⁶O₂ monolayer on NaCl(100) are reported for the first time. The polarization and coverage dependence of spectroscopic signals indicate that there is only one kind of adsorption site, in which the molecular axis is tilted 68° from the surface normal. The adsorbate layer grows in the form of constant-density islands. Plane group symmetry analysis reveals a unique structure: there are two tilted molecules per layer unit cell, arranged in herringbone fashion. This structure is in quantitative agreement with the photometric observations. Splitting of the molecular v₃ band is interpreted by a vibration-vibration coupling mechanism.     

Simplifying Access to Targeted Protein Degraders via Nickel Electrocatalytic Cross-Coupling

C−C linked glutarimide-containing structures with direct utility in the preparation of cereblon-based degraders (PROTACs, CELMoDs) can be assessed in a single step from inexpensive, commercial α-bromoglutarimide through a unique Brønsted-acid assisted Ni-electrocatalytic approach. The reaction tolerates a broad array of functional groups that are historically problematic and can be applied to the simplified synthesis of dozens of known compounds that have only been procured through laborious, wasteful, multi-step sequences. The reaction is scalable in both batch and flow and features a trivial procedure wherein the most time-consuming aspect of reaction setup is weighing out the starting materials.     

Organometallic Probe for the Electronics of Base‐Stabilized Group 11 Metal Cations

A number of trimetalloborides have been synthesized through the reactions of base‐stabilized coinage metal chlorides with a dimanganaborylene lithium salt in the hope of using this organometallic platform to compare and evaluate the electronics of these popular coinage metal fragments. The adducts of Cu^I, Ag^I, and Au^I ions, stabilized by tricyclohexylphosphine (PCy₃), N‐1,3‐bis(4‐methylphenyl)imidazol‐2‐ylidene (ITol), or 1‐(2,6‐diisopropylphenyl)‐3,3,5,5‐tetramethylpyrrolidin‐2‐ylidene (CAAC), with [{Cp(CO)₂Mn}₂B]^? were studied spectroscopically, structurally, and computationally. The geometries of the adducts fall into two classes, one symmetric and one asymmetric, each relying on the combined characteristics of both the metal and ligand. The energetic factors proposed as the causes of the structural differences were investigated by ETS‐NOCV (extended transition state‐natural orbitals for chemical valence) analysis, which showed the final geometry to be controlled by the competition between the tendency of the coinage metal to adopt a higher or lower coordination number and the willingness of the cationic fragment to participate in back‐bonding interactions.     

Controlling Regiochemistry in the Syntheses of Boraindanes from Diborane(4) Starting Materials

The reaction of tert‐butylisonitrile (tBuNC) with 1,2‐dihalo‐1,2‐diduryldiborane leads initially to the formation of the mono‐base adduct of the symmetrical diborane(4), which then undergoes an intramolecular cyclization resulting in the formation of a 1‐boraindane. This result is in contrast to a previously reported cyclization of a mono‐isonitrile adduct of an unsymmetrical 1,1‐pinacol‐2,2‐diaryldiborane(4), which results in the formation of a 1‐boraindane. This latter result is herein confirmed by the reaction of 1,1‐difluoro‐2,2‐dimesityldiborane(4) with tBuNC, which yielded the 2‐boraindane compound. The mechanism of the former reaction has been computationally elucidated, and the differences between this route and the pathway to 1‐boraindanes is discussed. These reactions further the understanding of the chemistry of the increasingly popular mono‐base adducts of diborane(4), demonstrate the versatility of isonitriles in comparison to standard two‐electron donors, and elucidate selective routes to boron‐containing polycyclics, such as those being proposed as analogues for conventional organic pharmaceuticals.     

The vapour pressures of n-octane determined using comparative ebulliometry

The vapour pressures of n-octane have been measured using comparative ebulliometry with water as the reference fluid. The results cover the temperature and pressure range (323.2 K, 6.7 kPa) to (563.3 K, 2301.7 kPa) and have been described by a Wagner style equation with a fractional standard deviation of 3.3×10⁻⁵ in the vapour pressure. The critical pressure p_c was treated as an adjustable parameter and the value of p_c=2482 kPa was obtained using the literature value for the critical temperature. An Antoine equation that describes the results below a pressure of 142 kPa with a standard deviation of 1.4 mK in the condensation temperature has also been obtained.