Coordination of Bimuth(III) to Cucurbit[8]uril. Preparation and X‐ray Structure of [{Bi(NO3)(H2O)5}2(Q8)][Bi(NO3)3(H2O)4]2[Bi(NO3)5]2·Q8·19H2O

Bi(NO₃)₃ reacts with cucurbit[8]uril, (Q8), in 3M HNO₃ to give the title complex whose structure includes three discrete Bi complexes: [{Bi(NO₃)(H₂O)₅}₂(Q8)]⁴⁺ (CN of Bi = 9, both NO₃^— and cucurbit[8]uril are bidentate), [Bi(NO₃)₅]^2— (CN of Bi = 10, all NO₃^— are bidentate), and [Bi(NO₃)₃(H₂O)₄] (CN of Bi = 10, all NO₃^— are bidentate).     

Cyclic Tribismuthide as a Piano Stool Complex Ligand – Synthesis and Crystal Structure of (η3‐Bi3)M(CO)33– (M = Cr,Mo)

The reactions between K₅Bi₄, [(C₆H₆)Cr(CO)₃] or [(C₇H₈)Mo(CO)₃], and [2.2.2]crypt in liquid ammonia yielded the compounds [K([2.2.2]crypt)]₃(η³‐Bi₃)M(CO)₃ · 10NH₃ (M = Cr, Mo), which crystallize isostructurally in P2₁/n. Both contain an 18 valence electron piano‐stool complex with a η³‐coordinated Bi₃‐ring ligand. The Bi–Bi distances range from 2.9560(5) to 2.9867(3) Å and are slightly shorter than known Bi–Bi single bonds but longer than Bi–Bi double bonds. The newly found compounds complete the family of similar complexes with E₃‐ring ligands (E = P‐Bi).     

Nitric Oxide Insertion Reactivity with the Bismuth–Carbon Bond: Formation of the Oximate Anion, [ON(C6H2tBu2O)]−, from the Oxyaryl Dianion, (C6H2tBu2O)2−

The first example of NO insertion into a Bi?C bond has been found in the direct reaction of NO with a Bi³⁺ complex of the unusual (C₆H₂tBu₂‐3,5‐O‐4)^2? oxyaryl dianionic ligand, namely, Ar′Bi(C₆H₂tBu₂‐3,5‐O‐4) [Ar′=2,6‐(Me₂NCH₂)₂C₆H₃] ( 1 ). The oximate complexes [Ar′Bi(ONC₆H₂‐3,5‐tBu₂‐4‐O)]₂(μ‐O) ( 3 ) and Ar′Bi(ONC₆H₂‐3,5‐tBu₂‐4‐O)₂ ( 4 ) were formed as a mixture, but can be isolated in pure form by reaction of NO with a Bi³⁺ complex of the [O₂C(C₆H₂tBu₂‐3‐5‐O‐4]^2? oxyarylcarboxy dianion, namely, Ar′Bi[O₂C(C₆H₂tBu₂‐3‐5‐O‐4)‐κ²O,O’]. Reaction of 1 with Ph₃CSNO gave an oximate product with (Ph₃CS)^1? as an ancillary ligand, (Ph₃CS)(Ar′)Bi(ONC₆H₂‐3,5‐tBu₂‐4‐O) ( 5 ).     

209Bi NQR study of bismuth(III) complexes

Potassium pentafluorobismuthate(III), nitrate-chloride Bi^III complexes MBiCl₃NO₃ (M=K, (NH₂)₂CNH₂), sulfate-chloride Bi^III complexes MBiCl₂SO₄ (M=K, Rb, NH₄, (NH₂(₂CNH₂), and Bi^III complexonates with the anions of ethylenediaminetetraacetic acid M[Bi(edta)]₂·nH₂O (M=Mg, Ca, Ni, Cd) and nitrilotriacetic acid Bi(nta)·2H₂O, and Bi(nta)·3thio·H₂O (thio is thiourea) were studied by²⁰⁹Bi NQR spectroscopy. A second-order phase transition was observed in K₂BiF₅ at 100 K. The compounds Bi(nta)·2H₂O, (NH₂)₂CNH₂BiCl₃NO₃, and MBiCl₂SO₄ (M=K, NH₄) are piezoelectrics. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2237–2240, November, 1998.     

Standard molar enthalpy of formation of [(C12H8N2)2Bi(O2NO)3] and its biological activity on Schizosaccharomyces pombe

The title complex [(C₁₂H₈N₂)₂Bi(O₂NO)₃] was synthesized by reaction of 1,10-phenanthroline (phen) and Bi(NO₃)₃·5H₂O. The structure of the complex was characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. An advanced solution-reaction isoperibol microcalorimeter was applied to determine the standard molar enthalpies of formation at 298.15 K of the complex and Bi(NO₃)₃·5H₂O, giving –(798.92 ± 5.99) and –(1986.87 ± 0.20) kJ mol⁻¹, respectively. The biological effect of the complex was evaluated by microcalorimetry on the growth of Schizosaccharomyces pombe (S. pombe). According to thermogenic curves, the corresponding thermokinetics and thermodynamic parameters were derived. The complex had good bioactivity on the growth metabolism of S. pombe, with the value of IC₅₀ being 2.8 × 10⁻⁵ mol L⁻¹.

     

Synthesis and Structure of (N,)C,N‐chelated Organoantimony(III) and Bismuth(III) Cations and Isolation of Their Adducts with Ag[CB11H12]

The treatment of N,C,N‐chelated antimony(III) and bismuth(III) chlorides [C₆H₃‐2,6‐(CH=NR)₂]MCl₂ [R = tBu and M = Sb ( 1 ) or Bi ( 2 ); R = Dmp and M = Sb ( 3 ) or Bi ( 4 )] (Dmp = 2,6‐Me₂C₆H₃) with one molar equivalent of Ag[CB₁₁H₁₂] led to a smooth formation of corresponding ionic pairs {[C₆H₃‐2,6‐(CH=NR)₂]MCl}⁺[CB₁₁H₁₂]^– [R = tBu and M = Sb ( 7 ) or Bi ( 8 ), R = Dmp and M = Sb ( 9 ) or Bi ( 10 )]. Similarly, the reaction of C,N‐chelated analogues [C₆H₂‐2‐(CH=NDip)‐4,6‐(tBu)₂]MCl₂ [M = Sb ( 5 ) or Bi ( 6 ), Dip = 2′,6′‐iPr₂C₆H₃] gave compounds {[C₆H₂‐2‐(CH=NDip)‐4,6‐(tBu)₂]MCl}⁺[CB₁₁H₁₂]^– [M = Sb ( 11 ) or Bi ( 12 )]. All compounds 7 – 12 were characterized with ¹H, ¹¹B and ¹³C{¹H} NMR spectroscopy, ESI‐mass spectrometry, IR spectroscopy, and molecular structures of 7 – 9 and 12 were determined by the help of single‐crystal X‐ray diffraction analysis. In contrast, all attempts to cleave also the second M–Cl bond in 7 – 12 using another molar equivalent Ag[CB₁₁H₁₂] remained unsuccessful. Nevertheless, the reaction between 7 (or 8 ) and Ag[CB₁₁H₁₂] produced unprecedented adducts of both reagents namely {[C₆H₃‐2,6‐(CH=NtBu)₂]SbCl}₂²⁺[Ag₂(CB₁₁H₁₂)₄]^2– ( 13 ) and {[C₆H₃‐2,6‐(CH=NtBu)₂]BiCl}⁺[Ag(CB₁₁H₁₂)₂]^– ( 14 ) in a reproducible manner. The molecular structures of these sparingly soluble compounds were determined by single‐crystal X‐ray diffraction analysis.     

Synthesis,crystal structure,thermal decomposition,and explosive properties of [Bi(tza)3] n (tza = tetrazole acetic acid)

A coordination compound based on tetrazole acetic acid (Htza) and bismuth(III), [Bi(tza)₃] _n , was synthesized and characterized by single crystal X-ray diffraction analysis, elemental analysis, FT-IR, and ¹H NMR spectroscopy. The crystallographic data show that the crystal belongs to monoclinic, P2₁/n space group, a?=?0.91968(19)?nm, b?=?0.94869(19)?nm, c?=?1.7824(4)?nm, β?=?101.488(3)°, and Z?=?4. The central bismuth(III) is nine-coordinate by three nitrogens from three tetrazole rings and six oxygens of the carboxylate of another three tza^? ions, with each tza^? tridentate, chelating, bridging coordination. The coordination bonds and the intramolecular hydrogen bonds make the complex pack into a layered structure in polymer form. The thermal decomposition mechanism of the title complex was investigated by DSC and TG-DTG techniques. Under nitrogen at a heating rate of 10°C?min^?1, thermal decomposition of the complex contains two intense exothermic processes between 217.4°C and 530.3°C in the DSC curve; the final decomposed residue at 570°C was Bi₂O₃. Sensitivity tests showed that [Bi(tza)₃] _n was sensitive to impact and flame stimulus.     

A Nano‐sized Supramolecule Beyond the Fullerene Topology

The reaction of [Cp^BnFe(η⁵‐P₅)] ( 1 ) (Cp^Bn=η⁵‐C₅(CH₂Ph)₅) with CuI selectively yields a novel spherical supramolecule (CH₂Cl₂)_3.4@[(Cp^BnFeP₅)₁₂{CuI}₅₄(MeCN)_1.46] ( 2 ) showing a linkage of the scaffold atoms which is beyond the Fullerene topology. Its extended CuI framework reveals an outer diameter of 3.7 nm—a size that has not been reached before using five‐fold symmetric building blocks. Furthermore, 2 shows a remarkable solubility in CH₂Cl₂, and NMR spectroscopy reveals that the scaffold of the supramolecule remains intact in solution. In addition, a novel 2D polymer [{Cp^BnFe(η⁵‐P₅)}₂{Cu₆(μ‐I)₂(μ₃‐I)₄}]_n ( 3 ) with an uncommon structural motif was isolated. Its formation can be avoided by using a large excess of CuI in the reaction with 1 .     

Structures of Bismuth(III) Complexonates in Aqueous Solutions Studied by 1H NMR Method

Aqueous solutions of bismuth(III) nitrilotriacetates BiNta · 2H₂O and M₃Bi(Nta)₂ ·nH₂O (M = Na, K, Rb, Cs, NH₄, CN₃H₆, n = 0–4) and the K[Bi(Edta)(Tu)₂] complex (Edta^4– is the anion of ethylenediaminetetraacetic acid, Tu is thiocarbamide) are studied by the ¹H NMR method at room temperature in the pH interval from 2 to 11. The formation of two types of bismuth nitrilotriacetate complexes in solutions is established. They are characterized by the presence (type 1) or absence (type 2) of the Bi–N bond. Their ratio, depending on the composition and pH of the solution, is determined. The K[Bi(Edta)(Tu)₂] compound in solutions occurs as one form. The pH values at which the substance begins to decompose are determined for each compound.     

Creating Iron– and Rhenium–Bismuth Bonds by Reactions with Organometallic Hydrides

While addition of [Cp₂ReH] to [Bi(OtBu)₃] leads to an equilibrium containing [Cp₂Re‐Bi(OtBu)₂], [{Cp₂Re}₂Bi(OtBu)], tBuOH and [CpRe(μ‐η⁵,η¹‐C₅H₄)Bi–ReCp₂], in the presence of water [{(Cp₂Re)₂Bi}₂O] ( 1 ) is formed selectively. Also [FpH] [Fp = (η⁵‐C₅H₅)(CO)₂Fe] can be employed as a precursor to form heterometallic bismuth compounds. Synthesis of [FpBi{OCH(CF₃)₂}₂]₂ ( 5 ) can be achieved by reaction of [FpH] with [Bi{OCH(CF₃)₂}₃(thf)]₂ and carboxylates [FpBi(O₂CR)₂]₂ are generated upon treatment of [FpH] with [Bi(O₂CR)₃] (R = CH₃, tBu). While the compounds [Fp‐Bi(O₂CR)₂]₂ can also be obtained from reactions with Fp‐Fp, they are formed far more readily using [FpH] as the precursor. They typically crystallize as dimers, like the alkoxide 5 . A monomeric compound of the type [Fp‐BiX₂] ( 6 ) could be isolated for X = thd (tetramethylheptanedionate), that is, after the reaction of [FpH] with [Bi(thd)₃]. Altogether, the results demonstrate the potential of [FpH] as a precursor for [Fp‐BiX₂] compounds, which are formed in reactions with bismuth alkoxides, carboxylates and diketonates.     

Bi−P Bond Homolysis as a Route to Reduced Bismuth Compounds and Reversible Activation of P4

Bismuth diphenylphosphanides Bi(NON^R)(PPh₂) (NON^R=[O(SiMe₂NR)₂], R=tBu, 2,6‐iPr₂C₆H₃, Aryl) undergo facile decomposition via single‐electron processes to form reduced Bi and P species. The corresponding derivatives Bi(NON^R)(PCy₂) are stable. Reaction of the isolated Bi^II radical ^.Bi(NON^Ar) with white phosphorus (P₄) proceeds with the reversible and selective activation of a single P?P bond to afford the bimetallic μ,η^1:1‐bicyclo[1.1.0]tetraphosphabutane compound.     

Synthesis,Structures, and Some Reactions of [(Thioacyl)thio]‐ and (Acylseleno)antimony and ‐bismuth Derivatives ((RCSS)xMR$\rm{_{{\bf 3 - }{\bf x}}^{\bf 1} }$ and (RCOSe)xMR$\rm{_{{\bf 3 - }{\bf x}}^{\bf 1} }$ with M = Sb,Bi and x = 1–3)

A series of [(thioacyl)thio]‐ and (acylseleno)antimony and [(thioacyl)thio]‐ and (acylseleno)bismuth, i.e., (RCSS)_xMR and (RCOSe)_xMR (M = Sb, Bi, R¹ = aryl, x = 1–3), were synthesized in moderate to good yields by treating piperidinium or sodium carbodithioates and ‐selenoates with antimony and bismuth halides. Crystal structures of (4‐MeC₆H₄CSS)₂Sb(4‐MeC₆H₄) ( 9b′ ), (4‐MeOC₆H₄COSe)₂Sb(4‐MeC₆H₄) ( 12c′ ), (4‐MeOC₆H₄COS)₂Bi(4‐MeC₆H₄) ( 15c′ ), and (4‐MeOC₆H₄CSS)₂BiPh ( 18c ) along with (4‐MeC₆H₄COS)₂SbPh ( 6b ) and (4‐MeC₆H₄COS)₃Sb ( 7b ) were determined (Figs. 1 and 2). These compounds have a distorted square pyramidal structure, where the aryl or carbothioato (= acylthio) ligand at the central Sb‐ or Bi‐atom is perpendicular to the plane that includes the two carbodithioato (= (thioacyl)thio), carboselenato (= acylseleno), or carbothioato ligand and exist as an enantiomorph pair. Despite the large atomic radii, the C?S ??? Sb distances in (RCSS)₂MR¹ (M = As, Sb, Bi; R¹ = aryl) and the C?O ??? Sb distances in (RCOS)_xMR (M = As, Sb, Bi; x = 2, 3) are comparable to or shorter than those of the corresponding arsenic derivatives (Tables 2 and 3). A molecular‐orbital calculation performed on the model compounds (MeC(E)E¹)_3?xMMe_x (M = As, Sb, Bi; E = O, S; E¹ = S, Se; x = 1, 2) at the RHF/LANL2DZ level supported this shortening of C?E ??? Sb distances (Table 4). Natural‐bond‐orbital (NBO) analyses of the model compounds also revealed that two types of orbital interactions n_S → σ and n_S → σ play a role in the (thioacyl)thio derivatives (MeCSS)_3?xMMe_x (x = 1, 2) (Table 5). In the acylthio‐MeCOSMMe₂ (M = As, Sb, Bi), n_O → σ contributes predominantly to the orbital interactions, but in MeCOSeSbMe₂, none of n_O → σ and n_O → σ contributes to the orbital interactions. The n_S → σ and n_S → σ orbital interactions in the (thioacyl)thio derivatives are greater than those of n_O → σ and n_O → σ in the acylthio and acylseleno derivatives (MeCOE)_3?xMMe_x (E = S, Se; M = As, Sb, Bi; x = 1, 2). ?The reactions of RCOSeSbPh₂ (R = 4‐MeC₆H₄) with piperidine led to the formation of piperidinium diphenylselenoxoantimonate(1?) (= piperidinium diphenylstibinoselenoite) (H₂NC₅H₁₀)⁺Ph₂SbSe^?, along with the corresponding N‐acylpiperidine (Table 6). Similar reactions of the bis‐derivatives (RCOSe)₂SbR¹ (R, R¹ = 4‐MeC₆H₄) with piperidine gave the novel di(piperidinium) phenyldiselenoxoantimonate(2?) (= di(piperidinium) phenylstibonodiselenoite), [(H₂NC₅H₁₀)⁺]₂(PhSbSe₂)^2?, in which the negative charges are delocalized on the SbSe₂ moiety (Table 6). Treatment of RCOSeSbR (R, R¹ = 4‐MeC₆H₄) with N‐halosuccinimides indicated the formation of Se‐(halocyclohexyl) arenecarboselenoates (Table 8). Pyrolysis of bis(acylseleno)arylbismuth at 150° gave Se‐aryl carboselenoates in moderate to good yields (Table 9).     

Reactions of σ-derivatives of trivalent titanium and vanadium with ketones

The interaction of Ph₃Ti with a number of ketones (acetone, 2-butanone, 3,3-dimethyl-2-butanone, benzophenone) was studied. The PhTi(OCR¹R²Ph)₂ complexes, where R¹=R²=Me (a), R¹=Me, R²=Et (b), R¹=Me, R²=t-Bu (c), and R¹=R²=Ph (d) were isolated in satisfactory yields. These compounds were characterized by ESR and IR spectroscopy and elemental analysis. Their thermal stability was determined by the DTA method. The reaction of Bn₃V with acetone gives V(OCMe₂Bn)₃. In analogy with titanium compounds, Bn₄V reacts with acetone at the ratio 12 to give Bn₂(OCMe₂Bn)₂.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1120–1122, June, 1994.     

Efficient one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones from aromatic aldehydes and their one-pot oxidation to quinazolin-4(3H)-ones catalyzed by Bi(NO3)3·5H2O: Investigating the role of the catalyst

An efficient and novel synthesis of 2,3-disubstituted 2,3-dihydroquinazolin-4(1H)-ones via one-pot, three-component reaction of isatoic anhydride, primary amines and aromatic aldehydes catalyzed by Bi(NO₃)₃·5H₂O under solvent-free conditions is described. Oxidation of these 2,3-dihydroquinazolin-4(1H)-ones to their quinazolin-4(3H)-ones was also successfully performed in the presence of Bi(NO₃)₃·5H₂O. This new method has the advantages of convenient manipulation, short reaction times, excellent yields, very easy work-up, and the use of commercially available, low cost and relatively non-toxic catalyst. The role of Bi(NO₃)₃·5H₂O was also investigated in these transformations.     

Bismuth(III) Complexes with N,N‐Di(2‐hydroxylethyl)aminodithiocarboxylate: Synthesis and Crystal Structure of {Bi[S2CN(C2H4OH)2]2[1, 10‐Phen]2(NO3)}·3H2O and (Bi[S2CN(C2H4OH)2]3}2

Two novel one‐ and two‐dimensional network structure bismuth(III) complexes with N, N‐di(2‐hydroxylethyl)‐aminodithiocarboxylate, {Bi[S₂CN(C₂H₄OH)₂]₂[1, 10‐Phen]₂(NO₃)}·3H₂O (1) and (Bi[S₂CN(C₂H₄OH)₂]₃)₂ (2) were synthesized. Their crystal and molecular structures were determined by X‐ray single crystal diffraction analysis. The crystal 1 belongs to monoclinic system with space group C2/c, a=1.6431(7) nm, b=2.4323(10) nm, c= 1.2646(5) nm, β=126. 237(5), Z=4, V=4.076(3) nm³, D_c=1.757 Mg/m^3, μ=4.598 mm^?1, F(000)=2156, R= 0.0211, wR=0.0369. The structure shows a distorted square antiprism configuration with eight‐coordination for the central Bi atom. The one‐dimensional chain structure was formed by H‐bonding interaction between hydroxyl group of N, N‐di(2‐hydroxylethyl)aminodithiocarboxylate ligands and crystal water. The crystal 2 belongs to monoclinic system with space group p2(1)/c, a= 1.1149(4) nm, b=2.1274(8) nrn, c=2.2107(8) nm, β=98.325(8)°, 2=4, V=5. 188(3) nm³, Dc=1.920 Mg/m³, μ=7.315 mm^?1, F(000)=2944, R=0.0565, wR=0.0772. The structure shows a distorted square antiprism configuration with eight‐coordination for the central Bi atoms. The two‐dimensional network structure was formed by H‐bonding interaction between adjacent molecules.     

Weak Pnictogen Bond with Bismuth: Experimental Evidence Based on Bi−P Through-Space Coupling

To study pnictogen bonding involving bismuth, flexible accordion-like molecular complexes of the composition [P(C₆H₄-o-CH₂SCH₃)₃BiX₃], (X=Cl, Br, I) have been synthesised and characterised. The strength of the weak and mainly electrostatic interaction between the Bi and P centres strongly depends on the character of the halogen substituent on bismuth, which is confirmed by single-crystal X-ray diffraction analyses, DFT and ab initio computations. Significantly, ²⁰⁹Bi–³¹P through-space coupling (J=2560 Hz) is observed in solid-state ³¹P NMR spectra, which is so far unprecedented in the literature, delivering direct information on the magnitude of this pnictogen interaction.     

p-Block Bismuth Nanoclusters Sites Activated by Atomically Dispersed Bismuth for Tandem Boosting Electrocatalytic Hydrogen Peroxide Production

Constructing electrocatalysts with p-block elements is generally considered rather challenging owing to their closed d shells. Here for the first time, we present a p-block-element bismuth-based (Bi-based) catalyst with the co-existence of single-atomic Bi sites coordinated with oxygen (O) and sulfur (S) atoms and Bi nanoclusters (Bi_clu) (collectively denoted as BiOS_SA/Bi_clu) for the highly selective oxygen reduction reaction (ORR) into hydrogen peroxide (H₂O₂). As a result, BiOS_SA/Bi_clu gives a high H₂O₂ selectivity of 95 % in rotating ring-disk electrode, and a large current density of 36 mA cm⁻² at 0.15 V vs. RHE, a considerable H₂O₂ yield of 11.5 mg cm⁻² h⁻¹ with high H₂O₂ Faraday efficiency of ∼90 % at 0.3 V vs. RHE and a long-term durability of ∼22 h in H-cell test. Interestingly, the experimental data on site poisoning and theoretical calculations both revealed that, for BiOS_SA/Bi_clu, the catalytic active sites are on the Bi clusters, which are further activated by the atomically dispersed Bi coordinated with O and S atoms. This work demonstrates a new synergistic tandem strategy for advanced p-block-element Bi catalysts featuring atomic-level catalytic sites, and the great potential of rational material design for constructing highly active electrocatalysts based on p-block metals.     

From Dibismuthenes to Three‐ and Two‐Coordinated Bismuthinidenes by Fine Ligand Tuning: Evidence for Aromatic BiC3N Rings through a Combined Experimental and Theoretical Study

The reduction of N,C,N‐chelated bismuth chlorides [C₆H₃‐2,6‐(CH?NR)₂]BiCl₂ [where R=tBu ( 1 ), 2′,6′‐Me₂C₆H₃ ( 2 ), or 4′‐Me₂NC₆H₄ ( 3 )] or N,C‐chelated analogues [C₆H₂‐2‐(CH?N‐2′,6′‐iPr₂C₆H₃)‐4,6‐(tBu)₂]BiCl₂ ( 4 ) and [C₆H₂‐2‐(CH₂NEt₂)‐4,6‐(tBu)₂]BiCl₂ ( 5 ) is reported. Reduction of compounds 1 – 3 gave monomeric N,C,N‐chelated bismuthinidenes [C₆H₃‐2,6‐(CH?NR)₂]Bi [where R=tBu ( 6 ), 2′,6′‐Me₂C₆H₃ ( 7 ) or 4′‐Me₂NC₆H₄ ( 8 )]. Similarly, the reduction of 4 led to the isolation of the compound [C₆H₂‐2‐(CH?N‐2′,6′‐iPr₂C₆H₃)‐4,6‐(tBu)₂]Bi ( 9 ) as an unprecedented two‐coordinated bismuthinidene that has been structurally characterized. In contrast, the dibismuthene {[C₆H₂‐2‐(CH₂NEt₂)‐4,6‐(tBu)₂]Bi}₂ ( 10 ) was obtained by the reduction of 5 . Compounds 6 – 10 were characterized by using ¹H and ¹³C NMR spectroscopy and their structures, except for 7 , were determined with the help of single‐crystal X‐ray diffraction analysis. It is clear that the structure of the reduced products (bismuthinidene versus dibismuthene) is ligand‐dependent and particularly influenced by the strength of the N→Bi intramolecular interaction(s). Therefore, a theoretical survey describing the bonding situation in the studied compounds and related bismuth(I) systems is included. Importantly, we found that the C₃NBi chelating ring in the two‐coordinated bismuthinidene 9 exhibits significant aromatic character by delocalization of the bismuth lone pair.     

Lead and HTM Free Stable Two‐Dimensional Tin Perovskites with Suitable Band Gap for Solar Cell Applications

Organic‐inorganic hybrid perovskites have attracted great attention over the last few years as potential light‐harvesting materials for efficient and cost‐effective solar cells. However, the use of lead iodide in state‐of‐the‐art perovskite devices may demonstrate an obstacle for future commercialization due to toxicity of lead. Herein we report on the synthesis and characterization of low dimensional tin‐based perovskites. We found that the use of symmetrical imidazolium‐based cations such as benzimidazolium (Bn) and benzodiimidazolium (Bdi) allow the formation of 2D perovskites with relatively narrow band gaps compared to traditional ‐NH₃⁺ amino groups, with optical band gap values of 1.81 eV and 1.79 eV for Bn₂SnI₄ and BdiSnI₄ respectively. Furthermore, we demonstrate that the optical properties in this class of perovskites can be tuned by formation of a quasi 2D perovskite with the formula Bn₂FASn₂I₇. Additionally, we investigate the change in band gap in the mixed Sn/Pb solid solution Bn₂Sn_xPb_x?1I₄. Devices fabricated with Bn₂SnI₄ show promising efficiencies of around 2.3 %.     

Synthesis,Characterization, and Photocatalytic Properties of Bismuth (III)‐benzene‐1,3,5‐tricarboxylate

{[Bi(BTC)(H₂O)₂] · H₂O}_n (H₃BTC = 1,3,5‐benzenetricarboxylic acid) was synthesized by an eco‐friendly hydrothermal method and characterized by single‐crystal X‐ray diffraction, IR and UV/Vis spectroscopy, photoluminescence (PL), and thermogravimetric analyses. The complex featured a 3D metal‐organic framework with Bi₂ secondary building units. In the complex, the central Bi³⁺ is nine‐coordinate, three central Bi atoms and three BTC^3– anions are interconnected into a ring with the dimension of 7.95 × 9.89 Ų. Moreover, the complex is decomposed at over 388 °C, showing its highly thermal stability. Further, the complex exhibits photocatalytic activity for the degradation of methyl orange (MO) solution under UV light irradiation, and its structure can keep consistent with the original one after 9 h photocatalytic reaction, indicating that it is also very stable under UV light. Therefore, it could be anticipated the novel coordination complex will be a stable ultraviolet light catalyst.