Identification of a prismatic P3N3 molecule formed from electron irradiated phosphine-nitrogen ices

Polyhedral nitrogen containing molecules such as prismatic P3N3 - a hitherto elusive isovalent species of prismane (C6H6) - have attracted particular attention from the theoretical, physical, and synthetic chemistry communities. Here we report on the preparation of prismatic P3N3 [1,2,3-triaza-4,5,6-triphosphatetracyclo[2.2.0.02,6.03,5]hexane] by exposing phosphine (PH3) and nitrogen (N2) ice mixtures to energetic electrons. Prismatic P3N3 was detected in the gas phase and discriminated from its isomers utilizing isomer selective, tunable soft photoionization reflectron time-of-flight mass spectrometry during sublimation of the ices along with an isomer-selective photochemical processing converting prismatic P3N3 to 1,2,4-triaza-3,5,6-triphosphabicyclo[2.2.0]hexa-2,5-diene (P3N3). In prismatic P3N3, the P–P, P–N, and N–N bonds are lengthened compared to those in, e.g., diphosphine (P2H4), di-anthracene stabilized phosphorus mononitride (PN), and hydrazine (N2H4), by typically 0.03–0.10 Å. These findings advance our fundamental understanding of the chemical bonding of poly-nitrogen and poly-phosphorus systems and reveal a versatile pathway to produce exotic, ring-strained cage molecules.

¹²⁹Xe ultra-fast Z spectroscopy enables micromolar detection of biosensors on a 1 T benchtop spectrometer

The availability of a benchtop nuclear magnetic resonance (NMR) spectrometer, of low cost and easily transportable, can allow detection of low quantities of biosensors, provided that hyperpolarized species are used. Here we show that the micromolar threshold can easily be reached by employing laser-polarized xenon and cage molecules reversibly hosting it. Indirect detection of caged xenon is made via chemical exchange, using ultra-fast Z spectroscopy based on spatio-temporal encoding. On this non-dedicated low-field spectrometer, several ideas are proposed to improve the signal.

¹²⁹Xe Ultrafast Z-spectroscopy enables micromolar detection of biosensors on a 1T benchtop spectrometer

The availability of a benchtop NMR spectrometer, of low cost and easily transportable, can allow detection of low quantities of biosensors, provided that hyperpolarized species are used. Here we show that the micromolar threshold can easily be reached, by employing laser-polarized xenon and cage-molecules reversibly hosting it. Indirect detection of caged xenon is made via chemical exchange, using ultrafast Z-spectroscopy based on spatio-temporal encoding. On this non-dedicated low-field spectrometer, several ideas are proposed to improve the signal.

Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH₄-selective, which is understood using ¹²⁹Xe, ¹H, and pulsed-field gradient NMR spectroscopy.

Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe-selective to CH₄-selective, which is understood using ¹²⁹Xe, ¹H, and pulsed-field gradient NMR spectroscopy.