RESUMEN
Li3Y1-xInxCl6 undergoes a phase transition from trigonal to monoclinic via an intermediate orthorhombic phase. Although the trigonal yttrium containing the end member phase, Li3YCl6, synthesized by a mechanochemical route, is known to exhibit stacking fault disorder, not much is known about the monoclinic phases of the serial composition Li3Y1-xInxCl6. This work aims to shed light on the influence of the indium substitution on the phase evolution, along with the evolution of stacking fault disorder using X-ray and neutron powder diffraction together with solid-state nuclear magnetic resonance spectroscopy, studying the lithium-ion diffusion. Although Li3Y1-xInxCl6 with x ≤ 0.1 exhibits an ordered trigonal structure like Li3YCl6, a large degree of stacking fault disorder is observed in the monoclinic phases for the x ≥ 0.3 compositions. The stacking fault disorder materializes as a crystallographic intergrowth of faultless domains with staggered layers stacked in a uniform layer stacking, along with faulted domains with randomized staggered layer stacking. This work shows how structurally complex even the "simple" series of solid solutions can be in this class of halide-based lithium-ion conductors, as apparent from difficulties in finding a consistent structural descriptor for the ionic transport.
RESUMEN
The UV photodissociation of pyruvic acid (PA) is studied in molecular beams using time-of-flight (TOF) mass spectroscopy and time-sliced velocity map imaging (VMI) following excitation to the first absorption band (S1 â S0) at 330-380 nm. CH3CO, HOCO, CO, CH3, and H are detected as photodissociation products. The photofragment yield (PFY) spectrum of the H product is recorded at 350-380 nm in He and Ar carrier gases. The spectrum shows sharp vibrational features reflecting the significant rotational cooling achieved in the molecular beam. It matches well the broad features observed in the room temperature absorption spectrum and indicates that the S1 state lives longer than a picosecond. The origin band of the S1 â S0 transition is identified at 26â¯710 cm-1, and progressions in the CH3 and C-C torsional modes are tentatively assigned. Kinetic energy release (KER) and angular distributions of CH3CO, HOCO, CO, CH3, and H fragments indicate that additional photon absorption from S1 to the S2/S3 states is facile and is followed by rapid dissociation to the observed fragments. On the basis of the energetics of the different dissociation pathways and analyses of the observed KER distributions, three-body fragmentation processes are proposed as major contributors to the formation of the observed products.
RESUMEN
Vertical and adiabatic excitation energies and oscillator strengths for valence and Rydberg states of hydroxycarbene (HCOH) and methylhydroxycarbene (CH3COH) are reported. The electronic properties were computed with equation-of-motion coupled-cluster methods with single and double substitution methods (EOM-CCSD) and the aug-cc-pVTZ basis set. The states' characters were analyzed by plotting natural transition orbitals (NTOs). The calculations demonstrate that the shape, size, and energy of each Rydberg orbital are affected to varying degrees by their interaction with the ion core. Likewise, the corresponding quantum defects reflect the Rydberg electron-ion core interactions. The results reported herein, combined with previously reported calculations of the photoelectron spectrum of HCOH, should help in designing strategies for state-selective detection of hydroxycarbenes via ionization.