A neon containing molecular anion is observed and analyzed.

The body-centered cubic (bcc) polymorph of NaCB11H12 has been stabilized at room temperature by high-energy mechanical milling. Temperature-dependent electrochemical impedance spectroscopy shows an optimum at 45-min milling time, leading to an rt conductivity of 4 mS cm–1. Mechanical milling suppresses an order–disorder phase transition in the investigated temperature range. Nevertheless, two main regimes can be identified, with two clearly distinct activation energies. Powder X-ray diffraction and 23Na solid-state NMR reveal two different Na+ environments, which are partially occupied, in the bcc polymorph. The increased number of available sodium sites w.r.t. ccp polymorph raises the configurational entropy of the bcc phase, contributing to a higher ionic conductivity. Mechanical treatment does not alter the oxidative stability of NaCB11H12. Electrochemical test on a symmetric cell (Na|NaCB11H12|Na) without control of the stack pressure provides a critical current density of 0.12 mA cm–2, able to fully charge/discharge a 120 mA h g–1 specific capacity positive electrode at the rate of C/2.

A fundamental understanding of cyclodextrin-closo-dodecaborate inclusion complexes is of great interest in supramolecular chemistry.

Nitro-functionalized undecahalogenated closo-dodecaborates [B 12 X 11 (NO 2)] 2À were synthesized in high purities and characterized by NMR, IR, and Ramans pectroscopy, single crystal X-diffraction, mass spectrometry,a nd gasphase ion vibrational spectroscopy.T he NO 2 substituent leads to an enhanced electronic and electrochemical stability compared to the parent perhalogenated [B 12 X 12 ] 2À (X = F-I) dianions evidenced by photoelectron spectroscopy,c yclic voltammetry,a nd quantum-chemical calculations. The stabilizing effect decreasesf rom X = Ft oX= I. Thermogravimetric measurementso ft he salts indicate the loss of the nitric oxide radical(NOC). The homolytic NOC eliminationf rom the dianion under very soft collisionale xcitation in gas-phase ion experiments results in the formation of the radical [B 12 X 11 O] 2À C.T heoretical investigations suggest that the loss of NOC proceeds via the rearrangementp roduct [B 12 X 11 (ONO)] 2À .T he O-bonded nitrosooxy structure is thermodynamically more stable than the N-bonded nitro structure and its formationb yr adicalr ecombination of [B 12 X 11 O] 2À C andN OC is demonstrated.

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