Gallium phosphides GAmPn (m + n = 2–5) and their anions: Structures,electron affinities,and vibrational frequencies

Geometries, electronic states, and electron affinities of Ga_mP_n and Ga_mP (m + n = 2–5) clusters have been examined using four hybrid and pure density functional theory (DFT) methods. Structural optimization and frequency analyses are performed with the basis of a 6‐311+G(2df) one‐particle basis set. The geometries are fully optimized with each DFT method independently. Three types of energy separations reported in this work are the adiabatic electron affinity (EA_ad), the vertical electron affinity (EA_vert), and the vertical detachment energy (VDE). The calculation results show that the singlet structures have higher symmetry than that of doublet structures. The best method for predicting molecular structures was found to be BLYP, while other methods generally underestimated bond lengths. The most reliable adiabatic electron affinities and vertical detachment energy, obtained at the BP86 and B3LYP level of theory, are predicted to be 2.22 and 2.10 eV (GaP), 2.51 and 2.46 eV (Ga₂P), 1.86 and 1.94 eV (GaP₂), 1.96 and 2.27 eV (GaP₃), 1.76 and 1.99 eV (Ga₃P), 1.79 and 2.14 eV (Ga₂P₂), 2.85 and 3.67 eV (GaP₄), 2.08 and 2.10 eV (Ga₄P), 2.90 and 3.17 eV (Ga₂P₃), and 2.70 and 3.37 eV (Ga₃P₂), respectively. Those for Ga₂P, Ga₃P, Ga₂P₂, Ga₄P, GaP₄, Ga₂P₃, and Ga₃P₂ are in good agreement with experiment, but the predicted EA_ad values for GaP, Ga₂P, GaP₂, and GaP₃ are larger than the available experimental values. For the vibrational frequencies of the Ga_mP_n series, the B3LYP method produces good predictions with the average error only ～10 cm^?1 from available experimental and theoretical values. The other three methods overestimate or underestimate the vibrational frequencies, with the worst predictions given by the BLYP method. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006     

Relationship between reduction potentials and electron affinities of fullerenes and their derivatives

A linear relationship was found between the first reduction potentials (E°_red) and electron affinities (EA) for fullerenes C₆₀ and C₇₀, their hydro- and fluoro-derivatives, and aromatic hydrocarbons: E°_red = –3.04 + 0.81·EA. This equation was used to estimate the unknown values of EA = 2.45 eV for C₆₀H₂, 2.47 eV for C₇₀H₂, –0.15 eV for C₇₀H_36—38, –0.41 eV for C₇₀H_44—46, and E°_red = –1.74—–1.91 V (vs. Fc^0/+) for C₆₀H₁₈.     

Optoelectronic properties of benzotrithiophene isomers: A density functional theory study

Benzotrithiophene (BTT) isomers were investigated using density functional theory (DFT) and time‐dependent DFT (TD‐DFT) with the aim to explore their structures, linear optical properties, vertical and adiabatic ionization potentials (IP_v and IP_a), electron affinities (EA_v and EA_a), and reorganization energies (λ). The computed bond lengths and bond angles at the B3LYP/6–311+G (d, p) level of theory are in good agreement with experimental crystal structures of the known BTTs. These molecules are planar with zero dihedral angle, making them an ideal backbone for high charge mobility. The UV–visible spectra of BTT isomers are in the range 280–360 nm. All BTT isomers have low hole/electron reorganization energies, which is the main characteristic of good hole/electron transporting materials, and these isomers in turn have potential applications in the field of organic materials.     

Anticooperativity of FH···Cl− hydrogen bonds in [FH)nCl]− clusters (n = 1…6)

The change of cooperativity of FH···Cl⁻ hydrogen bonds upon sequential addition of up to six FH molecules to the Cl⁻ first coordination sphere is investigated. The geometry of clusters [(FH) _nCl]⁻ (n = 1…6) was calculated (CCSD/aug-cc-pVDZ) and compared with [(FH) _nF]⁻ clusters. The geometry is determined by the symmetry-driven electrostatic requirements and also by the fact that formation of each new FH···Cl⁻ bond creates a depression in the chlorine's electron cloud on the opposite side of Cl⁻ (σ-hole), which limits the range of directions available for subsequent H-bond formation. The mutual influence of FH···Cl⁻ hydrogen bonds is anticooperative—the addition of each FH molecule weakens H-bonds by 23–16% and decreases their covalent character (as seen by LMO-EDA decomposition and QTAIM analysis). Anticooperativity effects could be tracked by spectroscopic parameters (frequency of local HF mode ν_FH, chemical shift δ_H, spin–spin coupling constants ¹J_FH, ^1hJ_HCl, ^2hJ_FCl and nuclear quadrupolar constants χ_18F, χ_D, and χ_35Cl. © 2019 Wiley Periodicals, Inc.     

On the evaluation of molecular electron affinities by approximate density functional theory

The ability of approximate Density Functional Theory to calculate molecular electron affinities has been probed by a series of calculations on the hydrides CH₃, NH₂, OH, and HC₂ as well as the multibonded species CN, BO, N₃, OCN, and NO₂. The simple Hartree–Fock Slater scheme lacks dynamic correlations and underestimates on the average the adiabatic electron affinities (EA_ad) by 0.7 eV. A considerable improvement is obtained by the Local Density Approximation (LDA) in which dynamic correlation is included. Values from LDA calculation underestimate, on the average, the adiabatic electron affinities by 0.4 eV. The best agreement with experiment is obtained by the LDA/NL scheme in which a nonlocal correction recently proposed by Becke is added to the LDA energy expression. The LDA/NL method underestimates EA_ad by 0.2 eV. It is concluded that the LDA/NL method affords EA_ad's in as good agreement with experiment as ab initio techniques in which electron correlation is taken into account by extensive configuration interaction. A full geometry optimization has been carried out on the nine neutral sample molecules as well as the corresponding anions.     

Study of small chlorine‐doped potassium clusters by thermal ionization mass spectrometry

The theoretical calculations have predicted that nonmetal‐doped potassium clusters can be used in the synthesis of a new class of charge‐transfer salts which can be considered as potential building blocks for the assembly of novel nanostructured material. In this work, K_nCl (n = 2–6) and K_nCl_n?1 (n = 3 and 4) clusters were produced by vaporization of a solid potassium chloride salt in a thermal ionization mass spectrometry. The ionization energies (IEs) were measured, and found to be 3.64 ± 0.20 eV for K₂Cl, 3.67 ± 0.20 eV for K₃Cl, 3.62 ± 0.20 eV for K₄Cl, 3.57 ± 0.20 eV for K₅Cl, 3.69 ± 0.20 eV for K₆Cl, 3.71 ± 0.20 eV for K₃Cl₂ and 3.72 ± 0.20 eV for K₄Cl₃. The K_nCl⁺ (n = 3–6) clusters were detected for the first time in a cluster beam generated by the thermal ionization source of modified design. Also, this work is the first to report experimentally obtained values of IEs for K_nCl⁺ (n = 3–6) and K_nCl_n?1⁺ (n = 3 and 4) clusters. The ionization energies for K_nCl⁺ and K_nCl_n?1⁺ clusters are much lower than the 4.34 eV of the potassium atom; hence, these clusters should be classified as ‘superalkali’ species. Copyright © 2012 John Wiley & Sons, Ltd.     

Structure and properties of iron oxide clusters: From Fe6 to Fe6O20 and from Fe7 to Fe7O24

Geometrical and electronic structures of the neutral and singly negatively charged Fe₆O_n and Fe₇O_m clusters in the range of 1 ≤ n ≤ 20 and 1 ≤ m ≤ 24, respectively, are computed using density functional theory with the generalized gradient approximation. The largest clusters in the two series, Fe₆O₂₀ and Fe₇O₂₄, can be described as Fe(FeO₄)₅ and Fe(FeO₄)₆ or alternatively as [FeO₅](FeO₃)₅ and [FeO₆](FeO₃)₆, respectively. The Fe₆O₂₀ and Fe₇O₂₄ clusters possess adiabatic electron affinities (EA_ad) of 5.64 eV and 5.80 eV and can be attributed to the class of hyperhalogens since FeO₄ is an unique closed‐shell superhalogen with the EA_ad of 3.9 eV. The spin character of the lowest total energy states in both series changes from ferromagnetic to ferrimagnetic or antiferromagnetic when the first Fe? O? Fe bridge is formed. Oxidation decreases substantially the polarizability per atom of the initial bare clusters; namely, from 5.98 ų of Fe₆ to 2.47 ų of Fe₆O₂₀ and from 5.67 ų of Fe₇ to 2.38 ų of Fe₇O₂₄. The results of our computations pertaining to the binding energies of O, Fe, O₂, and FeO in the Fe₇O_m series provide an explanation for the experimentally observed abundance of the iron oxide nanoparticles with stoichiometric compositions. © 2016 Wiley Periodicals, Inc.     

Dissociate electron attachment to monohalogenated benzenes

Formation of halogen negative ions by dissociative electron attachment on the halobenzenes C₆H₅Br, C₆H₅Cl and C₆H₅F is studied as a function of incident electron energy up to 7.5 eV by mass spectrometry. The threshold energies for Cl⁻ and Br⁻ provide a determination of the first electron affinities for C₆H₅Cl and C₆H₅Br. The absolute cross section for Ci⁻ formation from C₆H₅Cl was also measured.     

Formation of color centers and paramagnetic species upon reduction of poly(diphenylene phthalide) with metallic lithium in DMF

Reduction of poly(diphenylene phthalide) (PDP) with metallic lithium in DMF at room temperature was studied by electronic and ESR spectroscopies. The main feature of the process is the presence of a long induction period (about 50 to 80 min) which is probably caused by the formation of small lithium particles and by adsorption of the polymer on the metal. At least four types of nonparamagnetic color centers characterized by overlapping absorption bands at 570, 660, 750, and 810 nm were detected in the reduced solution. The amounts of all types of the color centers in the solution show a complex dynamic behavior. Reduction of the polymer in the bulk of the solution is due to lithium colloid particles which give rise to a narrow asymmetric ESR singlet (g = 2.0023, ΔH = 0.03 mT, A/B ≈ 1.1–1.8) and absorb light in the region λ ～300–400 nm. Paramagnetic species with quartet ESR signal with a splitting of 0.1 mT and g = 2.0045 observed in the solutions being reduced at a polymer concentration of 0.2 mol L^?1 were attributed to radical anions of terminal anthraquinone groups (TAGs). The electron affinities of some molecules simulating the phthalide-containing unit of the polymer backbone, TAG, and a defect anthrone group were calculated in the B3LYP/6-311+G(d,p) approximation. For diphenylphthalide, the vertical electron affinity EA_vert = 0.21 eV, the adiabatic electron affinity EA_ad = 0.66 eV, the effective electron affinity EA_eff (with allowance for cleavage of C-O bond in the phthalide ring) = 1.23 eV. For anthrone group, one has EA_ad ～1.2 eV and for anthraquinone group, EA_ad ～2 eV. The electron affinities of the model compounds were also calculated with inclusion of the energy of solvation in two solvents (DMF and DMSO) and the energy of polarization in the PDP film. The electronic spectra of some compounds chosen as models for the expected products of reduction (anions and dianions) of the main phthalide-containing fragments in the polymer, TAGs, and defect anthrone groups were also calculated by the TD DFT B3LYP/6-311G(d,p) method. The presence of three types of chemical electron traps and the possibility of manifestation of strong absorption bands of these anions and dianions in the spectral region 500–900 nm precludes unambiguous selection and assignment of complex experimental electronic spectra observed in the course of PDP reduction. The possible role of TAGs in the electronic and photophysical processes in PDP is discussed.     

Sr,Ba and Cd arsenates with the apatite‐type structure

X‐ray diffraction analysis of single crystals of three new arsenates adopting apatite‐type structures yielded formula Sr₅(AsO₄)₃F for strontium arsenate fluoride, (I), (Sr_1.66Ba_0.34)(Ba_2.61Sr_0.39)(AsO₄)₃Cl for strontium barium arsenate chloride, (II), and Cd₅(AsO₄)₃Cl_0.58(OH)_0.42 for cadmium arsenate hydroxide chloride, (III). All three structures are built up of isolated slightly distorted AsO₄ tetrahedra that are bridged by Sr²⁺ in (I), by Sr²⁺/Ba²⁺ in (II) and by Cd²⁺ in (III). Compounds (I) and (II) represent typical fluorapatites and chlorapatites, respectively, with F⁻ at the 2a (0, 0, ) site and Cl⁻ at the 2b (0, 0, 0) site of P6₃/m. In contrast, in (III), due to the requirement that the smaller Cd²⁺ cation is positioned closer to the channel Cl⁻ anion (partially substituted by OH⁻), the anion occupies the unusual 2a (0, 0, ) site. Therefore, Cl⁻ is similar to F⁻ in (I), coordinated by three A2 cations, unlike the octahedrally coordinated Cl⁻ in (II) and other ordinary chlorapatites. Furthermore, in (III), using FT–IR studies, we have inferred the existence of H⁺ outside the channel in oxyhydroxyapatites and provided possible atomic coordinates for a H atom in HAsO₄²⁻, leading to a proposed formulation of the compound as Cd₅(AsO₄)_3−x(HAsO₄)_xCl_0.58(OH)_{0.42−x−(y/2)}O_x+(y/2)□_y/2.     

Constitutional Isomerism of BiW6Cl15: (BiCl)[W6Cl14] and (BiCl2)[W6Cl13]

The compound (BiCl)[W₆Cl₁₄] was previously characterized as a product of the reduction of tungsten hexachloride with elemental bismuth. Another modification of BiW₆Cl₁₅ is now presented as (BiCl₂)[W₆Cl₁₃], based on the results of an X‐ray single crystal structure determination (space group P2₁/c, a = 1354.3(2) pm, b = 1234.4(2) pm, c = 1538.9(2) pm, and β = 118.76(1) °). The structure of (BiCl₂)[W₆Cl₁₃] contains chains of [(W₆Cl₈ⁱ)Cl₄^aCl_2/2^a–a]^– clusters bridged by chlorine atoms. The (BiCl₂)⁺ counterion exhibits two short Bi–Cl distances of 244.1(4) and 245.9(3) pm, respectively.     

The double-layered hydro­xide 3CaO·Al2O3·0.5CaBr2·0.5CaCl2·10H2O

The title compound, calcium oxide–dialuminium trioxide–calcium dibromide–calcium dichloride hydrate (3/1/0.5/0.5/10), also formulated as Ca₂Al(OH)₆Br_0.478Cl_0.522·2H₂O (dicalcium aluminium hydro­xide hemibromide hemichloride dihydrate), is a double-layered hydro­xide which belongs to the solid solution Ca₂Al(OH)₆Br_xCl_1−x·2H₂O, where x can vary from 0 to 1. Chloride and bromide anions of the negatively charged interlayer [Br_0.5Cl_0.5·2H₂O]⁻ share statistically the same crystallographic site. Al³⁺ and Ca²⁺ cations are coordinated by six and seven O atoms, respectively. All water mol­ecules are bonded to Ca²⁺ cations and assume the seventh coordination position. Anions in the interlayer are surrounded by ten H atoms. Br⁻ and Cl⁻ are therefore connected to the main layer by ten hydrogen bonds, six of 2.74 (2) Å and four of 2.52 (5) Å, where the donors are hydroxyl groups and water mol­ecules, respectively. Like the chloride equivalent, the title compound is a 6R polytype with trigonal space group Rc and lattice parameters a = 5.7537 (4) Å and c = 48.108 (4) Å.     

Poly(triazine imide) with intercalation of lithium and chloride ions [(C3N3)2(NH(x)Li(1-x))3⋅LiCl]: a crystalline 2D carbon nitride network

Poly(triazine imide) with intercalation of lithium and chloride ions (PTI/Li⁺Cl^?) was synthesized by temperature‐induced condensation of dicyandiamide in a eutectic mixture of lithium chloride and potassium chloride as solvent. By using this ionothermal approach the well‐known problem of insufficient crystallinity of carbon nitride (CN) condensation products could be overcome. The structural characterization of PTI/Li⁺Cl^? resulted from a complementary approach using spectroscopic methods as well as different diffraction techniques. Due to the high crystallinity of PTI/Li⁺Cl^? a structure solution from both powder X‐ray and electron diffraction patterns using direct methods was possible; this yielded a triazine‐based structure model, in contrast to the proposed fully condensed heptazine‐based structure that has been reported recently. Further information from solid‐state NMR and FTIR spectroscopy as well as high‐resolution TEM investigations was used for Rietveld refinement with a goodness‐of‐fit (χ²) of 5.035 and wRp=0.05937. PTI/Li⁺Cl^? (P6₃cm (no. 185); a=846.82(10), c=675.02(9) pm) is a 2D network composed of essentially planar layers made up from imide‐bridged triazine units. Voids in these layers are stacked upon each other forming channels running parallel to [001], filled with Li⁺ and Cl^? ions. The presence of salt ions in the nanocrystallites as well as the existence of sp²‐hybridized carbon and nitrogen atoms typical of graphitic structures was confirmed by electron energy‐loss spectroscopy (EELS) measurements. Solid‐state NMR spectroscopy investigations using ¹⁵N‐labeled PTI/Li⁺Cl^? proved the absence of heptazine building blocks and NH₂ groups and corroborated the highly condensed, triazine‐based structure model.     

Synthesen,Eigenschaften und Kristallstrukturen der Cluster‐Salze Bi6[PtBi6Cl12] und Bi2/3[PtBi6Cl12]

Syntheses, Properties and Crystal Structures of the Cluster Salts Bi₆[PtBi₆Cl₁₂] and Bi_2/3[PtBi₆Cl₁₂] Melting reactions of Bi with Pt and BiCl₃ yield shiny black, air insensitive crystals of the subchlorides Bi₆[PtBi₆Cl₁₂] and Bi_2/3[PtBi₆Cl₁₂]. Despite the substantial difference in the bismuth content the two compounds have almost the same pseudo‐cubic unit cell and follow the structural principle of a CsCl type cluster salt. Bi₆[PtBi₆Cl₁₂] consists of cuboctahedral [PtBi₆Cl₁₂]^2? clusters and Bi₆²⁺ polycations (a = 9.052(2) Å, α = 89.88(2)°, space group P 1, multiple twins). In the electron precise cluster anion, the Pt atom (18 electron count) centers an octahedron of Bi atoms whose edges are bridged by chlorine atoms. The Bi₆²⁺ cation, a nido cluster with 16 skeletal electrons, has the shape of a distorted octahedron with an opened edge. In Bi_2/3[PtBi₆Cl₁₂] the anion charge is compensated by weakly coordinating Bi³⁺ cations which are distributed statistically over two crystallographic positions (a = 9.048(2) Å, α = 90.44(3)°, space group ). Bi₆[PtBi₆Cl₁₂] is a semiconductor with a band gap of about 0.1 eV. The compound is diamagnetic at room temperature though a small paramagnetic contribution appears towards lower temperature.     

Conjugated polymers based on 1,8‐naphthalene monoimide with high electron mobility

1,4,8,9‐Naphthalene diimides (NDIs) with strong electron accepting ability and high stability are excellent building blocks for semiconductor polymers. However, 1,8‐naphthalene monoimide (NMI) with similar structure and energy levels as that of NDI has never been used to construct conjugated polymers because of synthetic difficulty. Herein, 3,6‐dibromo‐NMI (DBNMI) with bulky alkyl groups was obtained effectively in a four‐step synthesis, and three donor‐acceptor (D‐A) type conjugated polymers based on NMI were firstly prepared. These polymers have strong absorption in the range of 300–600 nm, low LUMO level of 3.68 eV, and moderate bandgaps of 2.18 eV. Space charge limiting current measurements indicate these polymers are typical electron transporting materials, and the highest electron mobility is up to 5.8 × 10⁻³ cm² V⁻¹ s⁻¹, which is close to the star acceptor based on NDI (N2200, 5.0 × 10⁻³ cm² V⁻¹ s⁻¹). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 276–281     

Superalkali Cations with Trivalent Anion MF<Subscript>6</Subscript><Superscript>3−</Superscript> (M = Al,Ga, Sc) as Central Core

A new series of polynuclear cations MF₆Li₄⁺ (M?=?Al, Ga, Sc) have been theoretically investigated based on density functional theory calculations. The regular octahedral MF₆ groups, although maintained their integrity, distorted to some degree upon the introduction of Li ligands. It has been found that the Li ligands prefer to occupy the bridge- or hollow-site of the MF₆ core. According to the MP2 results, the MF₆Li₄⁺ cations have lower vertical electron affinities (EA_vert, 2.618–3.212 eV) than the threshold of 3.89 eV, verifying their superalkali identity. Besides, the MF₆Li₄⁺ configurations with more dispersive Li ligands possess lower EA_vert values. More importantly, large HOMO–LUMO gaps, binding energies per atom (E_b), and positive fragmentation energies ensure the stability of these cations.     

Geometries,vibrational frequencies,and electron affinities of X2Cl (X=C,Si,Ge) clusters

Ab initio quantum chemical calculations have been performed on X₂Cl^? and X₂Cl (X = C, Si, Ge) clusters. The geometrical structures, vibrational frequencies, electronic properties and dissociation energies are investigated at the Hartree–Fock (HF), Møller–Plesset second‐ and fourth‐order (MP2, MP4), CCSD(T) level with the 6‐311+G(d) basis set. The X₂Cl (X = C, Si, Ge) and X₂Cl^? (X = Si, Ge) take a bent shape obtained at the ground state, while C₂Cl^? has a linear structure. The impact on internal electron transfer between the X₂Cl and the corresponding anional clusters is studied. The three different types of electron affinities (EAs) at the CCSD(T) are reported. The most reliable adiabatic electronic affinities, obtained at the CCSD(T)/cc‐pvqz level of theory, are predicted to be 3.30, 2.62, and 1.98 eV for C₂Cl, Si₂Cl, and Ge₂Cl, respectively. The calculated EAs of C₂Cl and Ge₂Cl are in good agreement with theoretical results reported. The correlation effects and basis sets effects on the geometrical structures and dissociation energies are discussed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

Cluster Compounds with Oxidised,Hexanuclear [Nb6Cli12Ia6]n− Anions (n=2 or 3)

Four mixed-halide cluster salts with chloride-iodide-supported octahedral Nb₆ metal atoms cores were prepared and investigated. The cluster anions have the formula [Nb₆Clⁱ₁₂I^a₆]ⁿ⁻ with Cl occupying the inner ligand sites and I the outer one. They are one- or two-electron-oxidized (n=2 or 3) with respect to the starting material cluster. (Ph₄P)⁺ and (PPN)⁺ function as counter cations. The X-ray structures reveal a mixed occupation of the outer sites for only one compound, (PPN)₃[Nb₆Clⁱ₁₂I^a_5.047(9)Cl^a_0.953]. All four compounds are obtained in high yield. If in the chemical reactions a mixture of acetic anhydride, CH₂Cl₂, and trimethylsilyl iodide is used, the resulting acidic conditions lead to form the two-electron-oxidised species (n=2) with 14 cluster-based electrons (CBEs). If only acetic anhydride is used, the 15 CBE species (n=3) is obtained in high yield. Interesting intermolecular bonding is found in (Ph₄P)₂[Nb₆Clⁱ₁₂I^a₆] ⋅ 4CH₂Cl₂ with I⋅⋅⋅I halogen bonding and π-π bonding interactions between the phenyl rings of the cations in (PPN)₃[Nb₆Clⁱ₁₂I^a_5.047(9)Cl^a_0.953]. The solubility of (Ph₄P)₂[Nb₆Clⁱ₁₂I^a₆] ⋅ 4CH₂Cl₂ has been determined qualitatively in a variety of solvents, and good solubility in the aprotic solvents CH₃CN, THF and CH₂Cl₂ has been found.     

PAH/PAH(CF3)n Donor/Acceptor Charge-Transfer Complexes in Solution and in Solid-State Co-Crystals

A solution, solid-state, and computational study is reported of polycyclic aromatic hydrocarbon PAH/PAH(CF₃)_n donor/acceptor (D/A) charge-transfer complexes that involve six PAH(CF₃)_n acceptors with known gas-phase electron affinities that range from 2.11(2) to 2.805(15) eV and four PAH donors, including seven CT co-crystal X-ray structures that exhibit hexagonal arrays of mixed π-stacks with 1/1, 1/2, or 2/1 D/A stoichiometries (PAH=anthracene, azulene, coronene, perylene, pyrene, triphenylene; n=5, 6). These are the first D/A CT complexes with PAH(CF₃)_n acceptors to be studied in detail. The nine D/A combinations were chosen to allow several structural and electronic comparisons to be made, providing new insights about controlling D/A interactions and the structures of CT co-crystals. The comparisons include, among others, CT complexes of the same PAH(CF₃)_n acceptor with four PAH donors and CT complexes of the same donor with four PAH(CF₃)_n acceptors. All nine CT complexes exhibit charge-transfer bands in solution with λ_max between 467 and 600 nm. A plot of E(λ_max) versus [IE(donor)−EA(acceptor)] for the nine CT complexes studied is linear with a slope of 0.72±0.03 eV eV⁻¹. This plot is the first of its kind for CT complexes with structurally related donors and acceptors for which precise experimental gas-phase IEs and EAs are known. It demonstrates that conclusions based on the common assumption that the slope of a CT E(λ_max) versus [IE−EA] plot is unity may be incorrect in at least some cases and should be reconsidered.     

Unprecedented Chiral Three-dimensional Hybrid Organic-Inorganic Perovskitoids

Chiral three-dimensional hybrid organic–inorganic perovskites (3D HOIPs) would show unique chiroptoelectronic performance due to the combination of chirality and 3D structure. However, the synthesis of 3D chiral HOIPs remains a significant challenge. Herein, we constructed a pair of unprecedented 3D chiral halide perovskitoids (R/S-BPEA)EA₆Pb₄Cl₁₅ ( 1-R/S ) (R/S-BPEA=(R/S)-1-4-Bromophenylethylammonium, EA=ethylammonium), in which the large chiral cations can be contained in the big “hollow” inorganic frameworks induced by mixing cations. Notably, 3D 1-R/S shows natural chiroptical activity, as evidenced by its significant mirror circular dichroism spectra and the ability to distinguish circularly polarized light. Moreover, based on the unique 3D structure, 1-S presents sensitive X-ray detection performance with a low detection limit of 398 nGy_air s⁻¹, which is 14 times lower than the regular medical diagnosis of 5.5 μGy_air s⁻¹. In this work, 3D chiral halide perovskitoids provide a new route to develop chiral material in spintronics and optoelectronics.