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A series of [Fe2Co2] squares encapsulated by different alkyldiamines are reported, which exhibit incomplete thermo-induced electron transfer and photo-responsive behaviors.

Mononuclear complexes within a particular coordination geometry have been well recognized for high-performance single-molecule magnets (SMMs), while the incorporation of such well-defined geometric ions into multinuclear complexes remains less explored. Using the rigid 2-(di(1

The engineering of switchable materials with controllable stimuli-responsive multistability remains challenging in materials science. Herein, we present syntheses and structural and magnetic studie...

The engineering of switchable molecules with dramatic magnetic change is currently among the most active areas in chemical research. Here, two cyanide-bridged mixed-valence {FeIII4FeII4} cubes were...

The self-assembly of Ni(ii) and 3,6-substituted tetrazine derivatives affords two Ni(ii) metallacycles (a molecular square and a molecular triangle) that feature tetrazine-based radical bridges and strong intramolecular magnetic couplings.

Combined substituent effects and hydrogen-bonding interactions modulate the electron transfer in cyanide bridged [Fe2Co2] squares: ferrimagnetism without ETCST for 1, while complete ETCST with T1/2 being 221 and 294 K for 2 and 3, respectively.

Utilizing two different Schiff base ligands, a Dy3 triangular 1 and a Dy3 + Dy3 compound 2 were obtained. The obvious transverse anisotropy and the larger dipole–dipole interactions induce the poor slow magnetic relaxation of 2.

The introduction of Keggin-type POMs of [PMo

A family of molecular capsules, {[(Tp*)Fe(CN)3Co(bpyC═N(CH2)7N═Cbpy)]2[X]2}·sol (1, X = ClO4, sol = 6DMF; 2, X = PF6, sol = 6DMF; 3, X = OTf, sol = 6DMF; 4, X = BPh4, sol = 2DMF; Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate; bpy = 2,2'-bipyridine), were prepared via the Schiff-base condensation of the aldehyde-substituted bpy (bpyCHO) and 1,7-diaminoheptane (H2N(CH2)7NH2). All the complexes contain the same cyanide-bridged cationic square cores ([Fe2Co2]2+), which are encapsuled by the flexible alkyl chains. Variable-temperature single-crystal X-ray diffraction, FT-IR spectra, and magnetic studies reveal the abrupt and complete, thermo- and photo-induced electron-transfer-coupled spin transition for 1-3, while the pure high-spin phase for 4. Such distinct behavior is attributed to the effective long-range cooperative interactions mediated by the intercluster π-π couplings in 1-3, which, however, are significantly blocked in 4 due to the steric effect of interstitial BPh4- anions. Furthermore, the shift in the thermally induced transition temperatures of 254 K for 1, 233 K for 2, and 187 K for 3, respectively, is likely correlated to the variable H···O and H···F interactions between the solvent molecules, anions, and the bipyridine ligands of the [Fe2Co2] squares, suggesting the significant anion-dependent effect in such a system.

Postsynthesis of the paramagnetic square-shaped complex {[(Tp*Me)Fe(μ-CN)2(CN)][Co(dmbpy)2]}2(BPh4)2·6MeCN·H2O [1, Tp*Me = tris(3,4,5-trimethylpyrazole)-borate; dmbpy = 4,4′-dimethyl-2,2′-bipyridin...

Aldehyde groups were intentionally equipped on the cyanide-bridged [Fe2Co2] square molecules: {[(Tp*)Fe(CN)3Co(bpyCHO)2]2-[PF6]2}·4MeOH (1, Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate; bpyCHO = 4-formyl-4′-methyl-2,2′-bipyridine), thus providing chemical-active windows for post-modification towards desired functions. In this contribution, by taking advantage of efficient Schiff-base condensation between the aldehyde-substituted bipyridine derivative (bpyCHO) and alkyl diamines (H2N-(CH2)nNH2), two discrete [Fe2Co2] compounds $$\{ {[({\rm{T}}{{\rm{p}}^ \ast }){\rm{Fe}}{({\rm{CN}})_3}{\rm{Co}}({\rm{bp}}{{\rm{y}}^{{\rm{C}} = {\rm{N}}{{({\rm{C}}{{\rm{H}}_2})}_{\boldsymbol{n}}}{\rm{N}} = {\rm{C}}}}{\rm{bpy}})]_2}{[{\rm{P}}{{\rm{F}}_6}]_2}\} \cdot 6{\rm{DMF}}\,({\bf{2}},\,n = 5;\,{\bf{3}},\,n = 7)$$ were prepared, where the cyanide-bridged [Fe2Co2] square cores were encapsulated by the flexible alkyl chains. Variable-temperature single-crystal X-ray diffraction and magnetic studies revealed complete thermo (T1/2 = 233 K (2) and 237 K (3)) and photo-induced electron transfer event accompanying spin transition between the diamagnetic [FeIILS2CoIIILS2] state and the paramagnetic [FeIIILS2CoIIHS2] state (LS, low spin; HS, high spin). In addition, the bidirectional switching between the two states was achieved with alternating laser irradiation at 808 and 532 nm at 10 K.

Introducing both tetrazine radical and azido bridges afforded two air-stable square complexes [MII4(bpztz•-)4(N3)4] (MII = Zn2+, 1; Co2+, 2; bpztz = 3,6-bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine), where the metal ions are cobridged by μ1,1-azido bridges and tetrazine radicals. Magnetic studies revealed strong antiferromagnetic metal-radical interaction with a coupling constant of -64.7 cm-1 in the 2J formalism in 2. Remarkably, 2 exhibits slow relaxation of magnetization with an effective barrier for spin reverse of 96 K at zero applied field.

The incorporation of two different cyanide building blocks of [(Tp

Three molecular squares with tunable transition temperature (T1/2) through the substitution of NCE− (E = S, Se, BH3) anions were prepared, demonstrating another effective way to tune the SCO properties of the [FeIII–CN–FeII] systems.

Two cyanide-bridged V-shaped isostructural trinuclear complexes [{(Tp*)FeIII(CN)3}2MII(bztpen)]·Sol (M = Fe, Sol = CH3OH·3H2O, 1; M = Co, Sol = 2CH3OH·2H2O, 2; bztpen = N-benzyl-N,N′,N′-tris(2-methylpyridyl)ethylenediamine; Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) were synthesized and characterized. The bztpen ligand serves as a tetradentate capping ligand around the inner metal ion, leaving one pyridyl group intact. Complex 1 exhibits a spin crossover (SCO) behavior between the {FeIIILSFeIIHSFeIIILS} and {FeIIILSFeIILSFeIIILS} spin isomers, while 2 shows both thermally- and photo-induced electron-transfer coupled spin transition (ETCST) property between the {FeIIILSCoIIHSFeIIILS} and {FeIIILSCoIIILSFeIILS} valence isomers. The total entropy changes for 1 and 2 between their corresponding two electronic states were found to be very close with the values of 87.46 and 84.49 J mol−1 K−1, respectively, indicating the comparable thermal energy barriers necessary for either an SCO or ETCST event for such a given system. Furthermore, both complexes undergo desolvation-induced irreversible and sharp magnetic change at high temperatures.

Two isostructural mononuclear lanthanide complexes [Ln(H2L)Cl3](Ln = Dy(1), Tb(2), H2L = 6,6′-(((oxybis(2,1-phenylene))bis-(azanylylidene))bis(methanylylidene))bis(2-methoxyphenol)) were synthesized by solvothermal reaction. In both complexes, the LnIII ions are seven-coordinated with a LnO4Cl3 coordination core in the C2v symmetry. Magnetic measurements reveal that DyIII complex 1 shows field-induced two-step magnetization relaxation processes with Ueff = 53.47 K (slow relaxation) and 26.94 K (fast relaxation), respectively. The analysis of energy levels and eigenstates suggests that the mixed ground state doublets result in the field induced single-ion magnet behaviour of complex 1. In addition, the magneto-structural correlation, including the easy magnetic axis of DyIII ion, was further discussed based on an electrostatic model calculation. This work gave another example of designing low-coordinated Ln-SIMs by utilizing a multidentate Schiff-base ligand with large steric hindrance.

Treatment of CoCl2·6H2O and tris(pyrazolyl-1-yl)borate tricyanoiron(III) anions at an elevated temperature (55 °C) afforded two less-common pearl-chain-like compounds, {[(TpR)Fe(CN)3CoCl2]2Co(DMF)4}·nDMF (1, TpR = Tp4-Me = hydridotris(4-methylpyrazol-1-yl)borate, n = 1 and 2, TpR = Tp*Me = hydridotris(3,4,5-trimethylpyrazol-1-yl)borate, n = 4.5), in which the 4-coordinate Co(II) ions and [(TpR)FeIII(CN)3]− units are alternately bridged by cyanide groups into squares, which are further linked with the 6-coordinate Co(II) ions into an infinite chain. Interestingly, the magnetic study revealed that 1 exhibits a typical single-chain magnet behaviour with an effective energy barrier of 28.0 K, while surprisingly no Glauber dynamics was observed for 2 despite their very similar structures. The variations of the local coordination environments of the cobalt ions and the cyanide linkages were evidenced, and they may account for the significant difference in their magnetic properties related to the global magnetic anisotropy and magnetic exchange of the chain.

The successful introduction of azide ions as secondary bridges into the FeIII–NiII cyanide system afforded two clusters and one unique 4(3),2-ribbon chain: [(bpzpy)2Ni2(μ2-1,1-N3)2{(pzTp)Fe(CN)3}2]...

Subnanometer single-chirality single-walled carbon nanotubes (SWCNTs) are of particular interest in multiple applications. Inspired by the interdisciplinary combination of redox active polyoxometalates and SWCNTs, here we report a cluster steric hindrance strategy by assembling polyoxometalates on the outer surface of subnanometer SWCNTs

Taking advantage of a rigid tetradentate ligand of bis(pyrazoly)(3-pyrazolypyridinyl)methane (PyPz3) and the [CuII(opba)]2- unit [opba4- = o-phenylenebis(oxamato)], the trinuclear complex [{CoII(PyPz3)}2CuII(opba)][ClO4]2·5MeCN·MeOH (1) was constructed, in which the CoII centers adopt a trigonal-prismatic geometry, while considerable intramolecular magnetic coupling was successfully introduced through the oxamido bridges, representing another very first example of single-molecule magnets marrying both selected coordination geometry and magnetic exchanges.

Two mononuclear trigonal prismatic Co(II) complexes [Co(tppm*)][BPh4]2 (1) and [Co(hpy)][BPh4]2·3CH2Cl2 (2) (tppm* = 6,6′,6″-(methoxymethanetriyl)tris(2-(1H-pyrazol-1-yl)pyridine; hpy = tris(2,2′-b...

Summary Trifluoromethylation has been used for nonfullerene acceptors, resulting in an ultra-narrow band-gap molecule named BTIC-CF3-γ. Compared to its fluorinated and chlorinated analogs, BTIC-CF3-γ possesses the most red-shifted absorptions. The single-crystal structure of BTIC-CF3-γ reveals that the cooperated π-π interactions from H aggregations of central fused cores and J aggregations of end groups lead to a three-dimensional (3D) interpenetrating network, which provides more electron-hopping junctions between different acceptor molecules. After blending with PBDB-TF, a champion power conversion efficiency (PCE) of 15.59% is realized, which is the highest value in reported ultra-narrow band-gap acceptors. Notably, a PCE of 16.50% is also achieved in BTIC-CF3-γ-based ternary devices due to their red-shifted absorptions. Overall, our results provide a visualized understanding of molecule packings of this family of acceptors and also demonstrate that trifluoromethylation is a useful strategy to design highly efficient ultra-low band-gap acceptors for the next nonfullerene solar devices.

Three cyanide-bridged {Fe2Fe} complexes of formula {[(TpR)Fe(CN)3]2[Fe(bnbpen)]}·S (TpR = Tp for 1·S, Tp3−Me for 2·S, and Tp* for 3·S, respectively; bnbpen = N,N′-bis-(2-naphthylmethyl)-N,N′-bis(2-picolyl)-ethylenediamine) have been prepared and characterized here. Single-crystal X-ray diffraction analysis revealed that all compounds feature right angled trinuclear structures with two [(TpR)Fe(CN)3]− units at the ends and one [Fe(bnbpen)]2+ at the centre. Besides the rich hydrogen bonds, remarkable π–π interactions are evidenced in all compounds between the intermolecular naphthyl and pyrazolyl rings. As a result, compounds 1·S and 2·S exhibit irreversible two-step and one-step spin-transitions, respectively, during the process of removing solvents, with T1/2 at 314 K and 376 K for 1·S and 350 K for 2·S, while compound 3·S shows a reversible one-step spin transition at relatively lower temperatures with T1/2 = 250 K, and what's more, an irreversible small magnetic change accompanied by the loss of lattice solvents was observed. The solvent-free compounds show SCO properties at lower temperatures than the corresponding solvated ones; however, the solvent-free compound 1 maintains an unexpected high-spin state and does not follow the trend that their transition temperatures decrease with the enhancement of the electron donor properties of the TpR ligands (Tp* < Tp3−Me < Tp), likely due to the more compact π–π stacking mode in comparison with those for compounds 2·S and 3·S.

The supramolecular self-assembly synthetic strategy provides a valid tool to obtain polynuclear Fe(II) complexes having effective communication between the metal centres and distinct spin crossover behaviour. Despite the great success in constructing various magnetic molecules, progress has not been made in SCO complexes based on azido bridges. In this article, the coordination-driven supramolecular assembly based on 3,6-substituted pyridazine and azide is presented to afford two Fe(II) grid-like complexes: [(L)4FeII4(N3)4][BPh4]4·sol (1, L = 3,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine and 2, L = 3,6-di(pyridin-2-yl)pyridazine). The substitution of pyridinyl groups in 2 instead of pyrazolyl ones in 1 led to the only example exhibiting spin-crossover behaviour (T1/2 = 230 K) among the azido-bridged complexes. In addition, a temperature-dependent photoluminescence study of 2 demonstrates a visible synergetic effect between the SCO event and the luminescence.

Semiconducting single-walled carbon nanotubes (s-SWCNTs) with a diameter of around 1.0-1.5 nm, which present bandgaps comparable to silicon, are highly desired for electronic applications. Therefore, the preparation of s-SWCNTs of such diameters has been attracting great attention. The inner surface of SWCNTs has a suitable curvature and large contacting area, which is attractive in host-guest chemistry triggered by electron transfer. Here we reported a strategy of host-guest molecular interaction between SWCNTs and inner clusters with designed size, thus selectively separating s-SWCNTs of expected diameters. When polyoxometalate clusters of ∼1 nm in size were filled in the inner cavities of SWCNTs, s-SWCNTs with diameters concentrated at ∼1.3-1.4 nm were selectively extracted with the purity of ∼98% by a commercially available polyfluorene derivative. The field-effect transistors built from the sorted s-SWCNTs showed a typical behavior of semiconductors. The sorting mechanisms associated with size-dependent electron transfer from nanotubes to inner polyoxometalate were revealed by the spectroscopic and in situ electron microscopic evidence as well as the theoretical calculation. The polyoxometalates with designable size and redox property enable the flexible regulation of interaction between the nanotubes and the clusters, thus tuning the diameter of sorted s-SWCNTs. The present sorting strategy is simple and should be generally feasible in other SWCNT sorting techniques, bringing both great easiness in dispersant design and improved selectivity.

Introducing both tetrazine radical and azido bridges afforded two air-stable square complexes [M

To elevate the performance of polymer solar cells (PSC) processed by non-halogenated solvents, a dissymmetric fused-ring acceptor BTIC-2Cl-γCF3 with chlorine and trifluoromethyl end groups has been designed and synthesized. X-ray crystallographic data suggests that BTIC-2Cl-γCF3 has a 3D network packing structure as a result of H- and J-aggregations between adjacent molecules, which will strengthen its charge transport as an acceptor material. When PBDB-TF was used as a donor, the toluene-processed binary device realized a high power conversion efficiency (PCE) of 16.31 %, which improved to 17.12 % when PC71ThBM was added as the third component. Its efficiency of over 17 % is currently the highest among polymer solar cells processed by non-halogenated solvents. Compared to its symmetric counterparts BTIC-4Cl and BTIC-CF3 -γ, the dissymmetric BTIC-2Cl-γCF3 integrates their merits, and has optimized the molecular aggregations with excellent storage and photo-stability, and also extending the maximum absorption peak in film to 852 nm. The devices exhibit good transparency indicating a potential utilization in semi-transparent building integrated photovoltaics (ST-BIPV).

The self-assembly of Co(ii) salts, pyridazine derivatives and azides afforded two azido-bridged [2×2] grid-type complexes {[(L)4CoII4(N3)4][BPh4]4}·sol (1, L = 3,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (pzdz) and sol = 4CH3CN·3CHCl3·2CH3OH and 2, L = 3,6-di(pyridin-2-yl)pyridazine (pydz) and sol = 4CH3CN). Upon comparison with other related grid-like complexes, the incorporation of end-on azido-bridges resulted in overall intramolecular ferromagnetic couplings, and thus endowed complexes 1 and 2 single molecule magnet behaviour with field-induced slow magnetic relaxation.

Treatment of CoCl2·6H2O and tris(pyrazolyl-1-yl)borate tricyanoiron(III) anions at 55 °C afforded a series of new Fe-Co polynuclear clusters: {Co2Cl2(DMF)4[(Tp4-Me)Fe(CN)3]2} (1; Tp4-Me = hydridotr...

Three cyanide-bridged {Fe

Two azido-bridged homospin Fe(II)/Co(II) coordination polymers [Fe2(Bzp)2(N3)4]n (1) and [Co4(Bzp)4(N3)8·(MeOH)2]n (2) (bzp = 2-benzoylpyridine) are prepared, which consist of one-dimensional neutral chains with pure EO-azido (μ2-1,1-N3) bridges. Magnetically, both 1 and 2 exhibit considerable intrachain ferromagnetic interactions which benefit from the EO-azido bridging mode, leading to typical single-chain magnet (SCM) behavior under both the “infinite-size” and “finite-size” regime and pronounced hysteresis loops. As far as the bridging network is concerned, complex 1 represents not only a rare example of homospin Fe(II)-based SCMs but also the first Fe(II) chain compound with pure EO-azido bridges.

The design of coordination sites around lanthanide ions has a strong impact on the sensitization of their luminescent signal. An imidodiphosphonate anionic binding site is attractive as it can be functionalized with "remote" sensitizer units, such as phenoxy moieties, namely, HtpOp, accompanied by an increased distance of the lanthanide from the ligand high-energy stretching vibrations which quench the luminescence signal, hence providing flexible shielding of the lanthanide. We report the formation and isolation of Ln(tpOp)3 complexes where Ln = Er, Gd, Tb, Dy, Eu, and Yb and the Y(tpOp)3 diamagnetic analogue. The complexes are formed from reaction of KtpOp and the corresponding LnCl3·6H2O salt either by titration and in situ formation or by mixing and isolation. All complexes are seven-coordinated by three tpOp ligand plus one ethanol molecule, except for Yb(tpOp)3 which has no solvent coordinated. Phosphorus NMR shows characteristic shifts to support the coordination of the lanthanide complexes. The complexes display visible and near-infrared luminescence with long lifetimes even for the near-infrared complexes which range from 3.3 μs for Nd(tpOp)3 to 20 μs for Yb(tpOp)3. The ligand shows more efficient sensitization than the imidodiphosphinate analogues for all lanthanide complexes with a notable quantum yield of the Tb(tpOp)3 complex at 45%. We attribute this to the properties of the remote sensitizer unit and its positioning further away from the lanthanide, eliminating quenching of high energy C-H vibrations from the ligand shell. Calculations of the ligand shielding support the photophysical properties of the complexes. These results suggest that these binding sites are promising in the further development of the lanthanide complexes in optoelectronic devices for telecommunications and new light emitting materials.

A new octacyanotungstate(V) based single chain magnet {[(Tpm)Co(DMF)W(CN)8]2[Co(DMF)4]·2DMF}n (1, Tpm = 1,1,1-trispyrazoylmethane), with an effective barrier of 39.7(3) cm−1 is reported. The Ising-like magnetic anisotropy of the chain originates from the nearly parallel local orientations of the Co(II) ions with the source of the uniaxial magnetic anisotropy being a trigonal distortion of the octahedral environment with the fac-tridentate capping Tpm ligand.

A linear trinuclear ferrous complex [FeII3(pymp)4(MeOH)2][BPh4]2·2MeOH (1) (Hpymp = 2-[(pyridine-2-ylimine)-methyl]phenol) was isolated and characterized both structurally and magnetically. A magnetic study revealed the ferromagnetic coupling (J = +3.54 cm-1) within the [FeII3] units and uniaxial magnetic anisotropy (D = -1.21 cm-1) of the molecule. Slow relaxation of the magnetization at below 5 K and an effective energy barrier of 26.0(2) cm-1 under a 1200 Oe applied dc field were evidenced. Moreover, clear magnetic hysteresis loops were observed at below 2.5 K, which further corroborated the single-molecule magnet behavior of 1.

Hydrothermal reactions of copper(II) and cobalt(II) salts with 1-tetrazole-phenyl-4-methylphosphonic acid yielded the coordination polymers [Cu(H 2 O)(HO 3 PCH 2 C 6 H 4 CN 4 )]·H 2 O ( 1 ·H 2 O) and [Co(H 2 O) 2 (HO 3 PCH 2 C 6 H 4 CN 4 H) 2 ]·2H 2 O ( 2 ·2H 2 O). Compound 1 ·H 2 O is two dimensional and is constructed from chains of trans -corner sharing, ‘4+2’ axially distorted {CuO 4 N 2 } octahedra. These chains are linked through the organic tethers of the ligands in the doubly deprotonated form{HO 3 PCH 2 C 6 H 4 CN 4 } 2− to propagate in two-dimensions. In contrast, compound 2 ·2H 2 O is one-dimensional and features {CoO 4 N 2 } octahedra linked through pairs of ligands in the singly deprotonated form {HO 3 PCH 2 C 6 H 4 CN 4 H} −1 , i.e. with the tetrazole terminus in the neutral form. The magnetic properties of compound 1 ·H 2 O reflect the structure where the Cu(II) ions are bridged by syn-syn phosphate and tetrazolate Cu-N-N-Cu bridges, with the former linkage likely to transfer ferromagnetic coupling whereas the latter leads to antiferromagnetic coupling. The two competing pathways lead to negligible overall coupling.

The preparation, structures, and spectroscopic properties of several molecular complexes and a one dimensional chain are described. A one-dimensional {trans-CrII(DMF)2(OTs)2}n (1) chain and mononuclear complexes of trans-[MII(OTs)2(DMF)4] (MII = Fe, 2; Co, 3) and [NiII(DMF)6][OTs]2 (4) stoichiometry are readily obtained from DMF/Et2O solutions containing the parent anhydrous tosylate salts. A hydrated analogue, trans-[FeII(OTs)2(OH2)2(DMF)2] (5), is obtained in minor quantities from solutions containing 2. Electronic spectra indicate all of the complexes adopt octahedral geometries in dimethylformamide solution. Room temperature susceptibility data indicates that high spin electronic configurations are preferred for 1 (S = 2), 2 (S = 2), and 3 (S = 3/2) while 4 adopts an S = 1 spin ground state. The solubility properties of the salts are also described.

Water samples from the two underground rivers (Fenghuang River and Longju River) and samples of the dry and wet deposition of atmospheric dissolved inorganic nitrogen were taken from the Longfeng karst trough valley located in the Zhongliang mountain in the suburbs of Chongqing from May 2017 to April 2018. Anions, cations

Taking advantages of both azide and cyanide bridges in magnetism and synthesis, an azido-cyanide mixed-bridged octanuclear [Fe

Three mononuclear metal complexes [MII(L-N3O2)(MeCN)2][BPh4]2 (M = Fe, 1; Co, 2; Ni, 3) were isolated and structurally characterized. Magnetic studies revealed uniaxial magnetic anisotropy for 1 (D = −17.1 cm−1) and 3 (D = −14.3 cm−1) and easy-plane magnetic anisotropy for 2 (D = +36.9 cm−1). Slow magnetic relaxation was observed for complexes 1 and 2 under an applied magnetic field, both of which are dominated by a Raman process.

A new tripodal hexadentate ligand of tris[6-(1 H-pyrazol-1-yl)pyridin-2-yl]methanol (tppm) was synthesized and explored for constructing the trigonal-prismatic cobalt(II) complex [Co(tppm)][ClO4]2·2CH3CN·H2O (1). Magnetic study showed that 1 exhibited large uniaxial magnetic anisotropy with a zero-field-splitting parameter of -80.7 cm-1 and typical single-molecule-magnet behavior.

Xueyu Cave watershed is located in Fengdu County in the outskirts of Chongqing, where rainfall events were monitored continuously from July 2015 to December 2017. We explored the variation of mass concentration of atmospheric dissolved inorganic nitrogen (NH