Difunctionalized {closo‐1‐CB11} Clusters: 1‐ and 2‐Amino‐12‐ethynylcarba‐closo‐dodecaborates

Carba‐closo‐dodecaborate anions with two functional groups have been synthesized via a simple two‐step procedure starting from monoamino‐functionalized {closo‐1‐CB₁₁} clusters. Iodination at the antipodal boron atom provided access to [1‐H₂N‐12‐I‐closo‐1‐CB₁₁H₁₀]^? ( 1 a ) and [2‐H₂N‐12‐I‐closo‐1‐CB₁₁H₁₀]^? ( 2 a ), which have been transformed into the anions [1‐H₂N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀]^? (R=H ( 1 b ), Ph ( 1 c ), Et₃Si ( 1 d )) and [2‐H₂N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀]^? (R=H ( 2 b ), Ph ( 2 c ), Et₃Si ( 2 d )) by microwave‐assisted Kumada‐type cross‐coupling reactions. The syntheses of the inner salts 1‐Me₃N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀ (R=H ( 1 e ), Et₃Si ( 1 f )) and 2‐Me₃N‐12‐RC?C‐closo‐1‐CB₁₁H₁₀ (R=H ( 2 e ), Et₃Si ( 2 f )) are the first examples for a further derivatization of the new anions. All {closo‐1‐CB₁₁} clusters have been characterized by multinuclear NMR and vibrational spectroscopy as well as by mass spectrometry. The crystal structures of Cs 1 a , [Et₄N] 2 a , K 1 b , [Et₄N] 1 c , [Et₄N] 2 c , 1 e , and [Et₄N][1‐H₂N‐2‐F‐12‐I‐closo‐1‐CB₁₁H₉]?0.5 H₂O ([Et₄N ]4 a ?0.5 H₂O) have been determined. Experimental spectroscopic data and especially spectroscopic data and bond properties derived from DFT calculations provide some information on the importance of inductive and resonance‐type effects for the transfer of electronic effects through the {closo‐1‐CB₁₁} cage.     

Anionic Gold(I) Complexes—Twelve‐ and Ten‐Vertex Monocarba‐closo‐borate Anions with Carbon–Gold σ Bonds

The anionic gold(I) complexes [1‐(Ph₃PAu)‐closo‐1‐CB₁₁H₁₁]^? ( 1 ), [1‐(Ph₃PAu)‐closo‐1‐CB₉H₉]^? ( 2 ), and [2‐(Ph₃PAu)‐closo‐2‐CB₉H₉]^? ( 3 ) with gold–carbon 2c–2e σ bonds have been prepared from [AuCl(PPh₃)] and the respective carba‐closo‐borate dianion. The anions have been isolated as their Cs⁺ salts and the corresponding [Et₄N]⁺ salts were obtained by salt metathesis reactions. The salt Cs‐ 3 isomerizes in the solid state and in solution at elevated temperatures to Cs‐ 2 with ΔH_iso=(?75±5) kJ mol^?1 (solid state) and ΔH^≠=(118±10) kJ mol^?1 (solution). The compounds were characterized by vibrational and multi‐NMR spectroscopies, mass spectrometry, elemental analysis, and differential scanning calorimetry. The crystal structures of [Et₄N]‐ 1 , [Et₄N]‐ 2 , and [Et₄N]‐ 3 were determined. The bonding parameters, NMR chemical shifts, and the isomerization enthalpy of Cs‐ 3 to Cs‐ 2 are compared to theoretical data.     

Synthesis and Characterization of 2‐Mono‐ and 1,2‐Diaminocarba‐closo‐dodecaborates M[1‐R‐2‐H2N‐closo‐CB11H10] (R=H,Ph, H2N,CyHN)

The first primary 2‐aminocarba‐closo‐dodecaborates [1‐R‐2‐H₂N‐closo‐CB₁₁H₁₀]^? (R=H ( 1 ), Ph ( 2 )) have been synthesized by insertion reactions of (Me₃Si)₂NBCl₂ into the trianions [7‐R‐7‐nido‐CB₁₀H₁₀]^3?. The difunctionalized species [1,2‐(H₂N)₂‐closo‐CB₁₁H₁₀] ( 3 ) and 1‐CyHN‐2‐H₃N‐closo‐CB₁₁H₁₀ (H‐ 4 ) have been prepared analogously from (Me₃Si)₂NBCl₂ and 7‐H₃N‐7‐nido‐CB₁₀H₁₂. In addition, the preparation of [Et₄N][1‐H₂N‐2‐Ph‐closo‐CB₁₁H₁₀] ([Et₄N]‐ 5 ) starting from PhBCl₂ and 7‐H₃N‐7‐nido‐CB₁₀H₁₂ is described. Methylation of the [1‐Ph‐2‐H₂N‐closo‐CB₁₁H₁₀]^? ion ( 2 ) to produce 1‐Ph‐2‐Me₃N‐closo‐CB₁₁H₁₀ ( 6 ) is reported. The crystal structures of [Et₄N]‐ 2 , [Et₄N]‐ 5 , and 6 were determined and the geometric parameters were compared to theoretical values derived from DFT and ab initio calculations. All new compounds were studied by NMR, IR, and Raman spectroscopy, MALDI mass spectrometry, and elemental analysis. The discussion of the experimental NMR chemical shifts and of selected vibrational band positions is supported by theoretical data. The thermal properties were investigated by differential scanning calorimetry (DSC). The pK_a values of 2‐H₃N‐closo‐CB₁₁H₁₁ (H‐ 1 ), 1‐H₃N‐closo‐CB₁₁H₁₀ (H‐ 7 ), and 1,2‐(H₃N)₂‐closo‐CB₁₁H₁₀ (H₂‐ 3 ) were determined by potentiometric titration and by NMR studies. The experimental results are compared to theoretical data (DFT and ab initio). The basicities of the aminocarba‐closo‐dodecaborates agree well with the spectroscopic and structural properties.     

Aza‐nido‐dodecaboranes and ‐borates from Aza‐closo‐dodecaboranes by the Addition of Neutral or Anionic Bases: Mechanism

The addition of neutral (L = py, NEt₃, NHEt₂, NH₂tBu) and anionic Lewis bases (X^‐ = OH^‐, Br^‐, N₃^‐, Me^‐, NHBu ^‐, NHtBu^‐, [FeCp(CO)₂]^‐) to aza‐closo‐dodecaboranes RNB₁₁H₁₁ ( 1 ) or to derivatives thereof with boron bound non‐hydrogen ligands yields nido‐clusters RNB₁₁H₁₁L or [RNB₁₁H₁₁X]^‐ or derivatives thereof, respectively, the non‐planar pentagonal aperture N—B4—B9—B8—B5 of which hosts a B8—B9 hydrogen bridge. The base is either bound to B8 ( 3 )or B4 ( 5 )or B2( 7 ). The structures of these adducts are concluded from ¹H and ¹¹B NMR including 2D‐NMR spectra, and in the case of MeNB₁₁H₁₁(NHEt₂) (type 3 ) also by a crystal structure analysis. With two of the adducts MeNB₁₁H₁₁L (L = py, NHEt₂), isomers of the type 3 , 5 , and 7 , and with two of the adducts, MeNB₁₁H₁₁(NH₂tBu) and {MeNB₁₁H₁₁[FeCp(CO)₂]}^‐, isomers of the type 3 and 7 could be identified. The position of boron‐bound ligands during the addition of bases to 1 shows, that only vertices of the ortho‐belt of 1 are involved in the opening process. A mechanism is made plausible that starts by the attack of the base at B2 of 1 and opening of the N‐B2 bond, denoted as a [3c, 1c]‐collocation, to give 2 with an endo‐H atom, whose migration into an adjacent bridge position and opening of a second B—N bond, denoted as a [3c, 2c]‐translocation, gives 3 ; this isomer can be transformed into 7 by a sequence of [3c, 2c]‐translocations via the isomers 4 , 5 , and 6 . The chiral type 3 species MeNB₁₁H₁₁L with L = NHEt₂, NH₂tBu undergo a rapid enantiomerization, for whose mechanism the exchange of the bridging and the amine‐H atom has been made plausible.     

Synthesis and Characterization of 11‐Amino‐3‐methoxy‐8‐substituted‐12‐aryl‐8,9‐dihydro‐7H‐chromeno[2,3‐b]quinolin‐10(12H)‐one Derivatives

A series of 2‐amino‐7‐methoxy‐4‐aryl‐4H‐chromene‐3‐carbonitrile compounds 2 were obtained by condensation of 3‐methoxyphenol with β‐dicyanostyrenes 1 in absolute ethanol containing piperidine. The intermediate enamines 3 were prepared by compounds 2 with 5‐substituted‐1,3‐cyclohexanedione using p‐toluenesuflonic acid (TsOH) as catalyst. The title compounds 11‐amino‐3‐methoxy‐8‐substituted‐12‐aryl‐8,9‐dihydro‐7H‐chromeno[2,3‐b]quinolin‐10(12H)‐one 4 were synthesized by cyclization of the intermediate enamines 3 in THF with K₂CO₃ /Cu₂Cl₂ as catalyst. The structures of all compounds were characterized by elemental analysis, IR, MS, and ¹H NMR spectra. The crystal structure of compound 4i was determined by single‐crystal X‐ray diffraction analysis.     

Different nucleobase orientations in two cyclic 2′,3′‐phosphates of purine ribonucleosides: Et3NH(2′,3′‐cAMP) and Et3NH(2′,3′‐cGMP)·H2O

The crystal structures of triethyl­ammonium adenosine cyclic 2′,3′‐phosphate {systematic name: triethyl­ammonium 4‐(6‐amino­purin‐9‐yl)‐6‐hydroxy­methyl‐2‐oxido‐2‐oxoperhydro­furano[3,4‐c][1,3,2]dioxaphosphole}, Et₃NH(2′,3′‐cAMP) or C₆H₁₆N⁺·C₁₀H₁₁N₅O₆P⁻, (I), and guanosine cyclic 2′,3′‐phosphate monohydrate {systematic name: triethyl­ammonium 6‐hydroxy­methyl‐2‐oxido‐2‐oxo‐4‐(6‐oxo‐1,6‐dihydro­purin‐9‐yl)perhydro­furano[3,4‐c][1,3,2]dioxaphosphole monohydrate}, [Et₃NH(2′,3′‐cGMP)]·H₂O or C₆H₁₆N⁺·C₁₀H₁₁N₅O₇P⁻·H₂O, (II), reveal different nucleobase orientations, viz. anti in (I) and syn in (II). These are stabilized by different inter‐ and intra­molecular hydrogen bonds. The structures also exhibit different ribose ring puckering [₄E in (I) and ³T₂ in (II)] and slightly different 1,3,2‐dioxaphospho­lane ring conformations, viz. envelope in (I) and puckered in (II). Infinite ribbons of 2′,3′‐cAMP⁻ and helical chains of 2′,3′‐cGMP⁻ ions, both formed by O—H⋯O, N—H⋯X and C—H⋯X (X = O or N) hydrogen‐bond contacts, characterize (I) and (II), respectively.     

Coordination of a closo‐Cluster at Rhodium and Iridium

Stanna‐closo‐dodecaborate [Bu₃MeN]₂[SnB₁₁H₁₁] reacts as a nucleophile with the rhodium and iridium electrophiles of type [Cp*M(bipy′)Cl][BF₄] under formation of a transition metal tin bond. The zwitterionic molecules [Cp*M(bipy′)(SnB₁₁H₁₁)] (with M = Rh, Ir) were characterized by NMR spectroscopy, elemental analyses and X‐ray crystal structure analyses. A high dipole moment of 25.67 D was calculated by DFT methods in the case of the rhodium derivative.     

A new one‐dimensional ZnII coordination polymer based on 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole and benzene‐1,2‐dicarboxylate

Multidentate N‐heterocyclic compounds form a variety of metal complexes with many intriguing structures and interesting properties. The title coordination polymer, catena‐poly[zinc(II)‐bis{μ‐2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole}‐κ²N³:N^3′;N^3′:N³‐zinc(II)‐bis(μ‐benzene‐1,2‐dicarboxylato)‐κ²O¹:O²;κ³O¹,O^1′:O²], [Zn₂(C₈H₄O₄)₂(C₁₁H₁₀N₄)₂]_n, has been synthesized by the reaction of Zn(NO₃)₂ with 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole (imb) and benzene‐1,2‐dicarboxylic acid (H₂bdic) under hydrothermal conditions. There are two crystallographically distinct imb ligands [imb(A) and imb(B)] in the structure which adopt very similar coordination geometries. The imb(A) ligand bridges two symmetry‐related Zn1 ions, yielding a binuclear [(Zn1)₂{imb(A)}₂] unit, and the imb(B) ligand bridges two symmetry‐related Zn2 ions resulting in a binuclear [(Zn2)₂{imb(B)}₂] unit. The above‐mentioned binuclear units are further connected alternately by pairs of bridging bdic²⁻ ligands, forming an infinite one‐dimensional chain. These one‐dimensional chains are further connected through N—H...O hydrogen bonds, leading to a two‐dimensional layered structure. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.     

A new two‐dimensional CoII coordination polymer based on bis[4‐(2‐methyl‐1H‐imidazol‐1‐yl)phenyl] ether and biphenyl‐4,4′‐diyldicarboxylic acid: synthesis,crystal structure and photocatalytic degradation activity

A novel two‐dimensional Co^II coordination framework, namely poly[(μ₂‐biphenyl‐4,4′‐diyldicarboxylato‐κ²O⁴:O^4′){μ₂‐bis[4‐(2‐methyl‐1H‐imidazol‐1‐yl)phenyl] ether‐κ²N³:N^3′}cobalt(II)], [Co(C₁₄H₈O₄)(C₂₀H₁₈N₄O)]_n, has been prepared and characterized by IR, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. The crystal structure reveals that the compound has an achiral two‐dimensional layered structure based on opposite‐handed helical chains. In addition, it exhibits significant photocatalytic degradation activity for the degradation of methylene blue.     

New fluorous ponytailed 4‐[(2,2,2‐trifluoroethoxy)methyl]pyridinium halide salts

It is possible that fluorous compounds could be utilized as directing forces in crystal engineering for applications in materials chemistry or catalysis. Although numerous fluorous compounds have been used for various applications, their structures in the solid state remains a lively matter for debate. The reaction of 4‐[(2,2,2‐trifluoroethoxy)methyl]pyridine with HX (X = I or Cl) yielded new fluorous ponytailed pyridinium halide salts, namely 4‐[(2,2,2‐trifluoroethoxy)methyl]pyridinium iodide, C₈H₉F₃NO⁺·I⁻, (1), and 4‐[(2,2,2‐trifluoroethoxy)methyl]pyridinium chloride, C₈H₉F₃NO⁺·Cl⁻, (2), which were characterized by IR spectroscopy, multinuclei (¹H, ¹³C and ¹⁹F) NMR spectroscopy and single‐crystal X‐ray diffraction. Structure analysis showed that there are two types of hydrogen bonds, namely N—H…X and C—H…X. The iodide anion in salt (1) is hydrogen bonded to three 4‐[(2,2,2‐trifluoroethoxy)methyl]pyridinium cations in the crystal packing, while the chloride ion in salt (2) is involved in six hydrogen bonds to five 4‐[(2,2,2‐trifluoroethoxy)methyl]pyridinium cations, which is attributed to the smaller size and reduced polarizability of the chloride ion compared to the iodide ion. In the IR spectra, the pyridinium N—H stretching band for salt (1) exhibited a blue shift compared with that of salt (2).     

Self‐Assembly of Discrete Copper(I)‐Halide Complexes with Diacylthioureas

Three diacylthioureas 1,4‐C₆H₄[C(O)NHC(S)NHAr]₂ (Ar = 2,6‐iPr₂C₆H₃) ( L¹ , 1 ), 1,3‐C₆H₄[C(O)NHC(S)NHAr]₂ ( L² , 2 ), and 1,3‐C₆H₄[C(O)NHC(S)NHAr′]₂ (Ar′ = 2,6‐Me₂C₆H₃) ( L³ , 3 ) were synthesized and characterized. The Cu^I complexes from the reactions of bipodal ligands Lⁿ with CuX (X = Cl, Br, I) were structurally investigated by single‐crystal X‐ray diffraction methods. Treatment of L¹ with CuX gave the metallamacrocyclic complexes ( L¹ CuX)₂ [X = Cl ( 4 ), Br ( 5 ), I ( 6 )] with the ligand to metal in a ratio of 2:2, where both sulfur and halide anions function as terminal substituents. In contrast, when L² or L³ was reacted with CuBr, the two Lⁿ ligands coordinate to four copper atoms each in a bridging and terminal fashion to yield [ Lⁿ (CuBr)₂]₂ [n = 2 ( 7 ), 3 ( 8 )]. The obtained S₄Cu₄Br₄ core contains all four bromide anions in bridging positions. The reaction of L³ with CuX (X = Cl, I) gave the 3:3 trinuclear complexes ( L³ CuX)₃ [X = Cl ( 9 ) I ( 10 )], interconnected by halide bridges. The obtained diacylthioureas ( 1 – 3 ) and their Cu^I complexes ( 4 – 10 ) were also characterized by elemental analysis, FT‐IR, ¹H and ¹³C NMR spectroscopy.     

Guest‐, Light‐ and Thermally‐Modulated Spin Crossover in [FeII2] Supramolecular Helicates

A new bis(pyrazolylpyridine) ligand (H₂L) has been prepared to form functional [Fe₂(H₂L)₃]⁴⁺ metallohelicates. Changes to the synthesis yield six derivatives, X@[Fe₂(H₂L)₃]X(PF₆)₂?xCH₃OH ( 1 , x=5.7 and X=Cl; 2 , x=4 and X=Br), X@[Fe₂(H₂L)₃]X(PF₆)₂?yCH₃OH?H₂O ( 1 a , y=3 and X=Cl; 2 a , y=1 and X=Br) and X@[Fe₂(H₂L)₃](I₃)₂?3 Et₂O ( 1 b , X=Cl; 2 b , X=Br). Their structure and functional properties are described in detail by single‐crystal X‐ray diffraction experiments at several temperatures. Helicates 1 a and 2 a are obtained from 1 and 2 , respectively, by a single‐crystal‐to‐single‐crystal mechanism. The three possible magnetic states, [LS–LS], [LS–HS], and [HS–HS] can be accessed over large temperature ranges as a result of the structural nonequivalence of the Fe^II centers. The nature of the guest (Cl^? vs. Br^?) shifts the spin crossover (SCO) temperature by roughly 40 K. Also, metastable [LS–HS] or [HS–HS] states are generated through irradiation. All helicates (X@[Fe₂(H₂L)₃])³⁺ persist in solution.     

Synthesis of Some New 2‐Oxo‐N‐[(10H‐phenothiazin‐10‐yl)alkyl] Derivatives of Azetidine‐1‐carboxamides

The synthesis of a new series of 4‐aryl‐3‐chloro‐2‐oxo‐N‐[3‐(10H‐phenothiazin‐10‐yl)propyl]azetidine‐1‐carboxamides, 4a – 4m , is described. Phenothiazine on reaction with Cl(CH₂)₃Br at room temperature gave 10‐(3‐chloropropyl)‐10H‐phenothiazine ( 1 ), and the latter reacted with urea to yield 1‐[3‐(10H‐phenothiazin‐10‐yl)propyl]urea ( 2 ). Further reaction of 2 with several substituted aromatic aldehydes led to N‐(arylmethylidene)‐N′‐[3‐(phenothiazin‐10‐yl)propyl]ureas 3a – 3m , which, on treatment with ClCH₂COCl in the presence of Et₃N, furnished the desired racemic trans‐2‐oxoazetidin‐1‐carboxamide derivatives 4a – 4m . The structures of all new compounds were confirmed by IR, and ¹H‐ and ¹³C‐NMR spectroscopy, FAB mass spectrometry, and chemical methods.     

Conformational study of (Z)‐5‐(4‐chlorobenzylidene)‐2‐[4‐(2‐hydroxyethyl)piperazin‐1‐yl]‐3H‐imidazol‐4(5H)‐one in different environments: insight into the structural properties of bacterial efflux pump inhibitors

The 2‐amine derivatives of 5‐arylidene‐3H‐imidazol‐4(5H )‐one are a new class of bacterial efflux pump inhibitors, the chemical compounds that are able to restore antibiotic efficacy against multidrug resistant bacteria. 5‐Arylidene‐3H‐imidazol‐4(5H )‐ones with a piperazine ring at position 2 reverse the mechanisms of multidrug resistance (MDR) of the particularly dangerous Gram‐negative bacteria E. coli by inhibition of the efflux pump AcrA/AcrB/TolC (a main multidrug resistance mechanism in Gram‐negative bacteria, consisting of a membrane fusion protein, AcrA, a Resistant‐Nodulation‐Division protein, AcrB, and an outer membrane factor, TolC). In order to study the influence of the environment on the conformation of (Z )‐5‐(4‐chlorobenzylidene)‐2‐[4‐(2‐hydroxyethyl)piperazin‐1‐yl]‐3H‐imidazol‐4(5H )‐one, ( 3 ), two different salts were prepared, namely with picolinic acid {systematic name: 4‐[(Z )‐4‐(4‐chlorobenzylidene)‐5‐oxo‐3,4‐dihydro‐1H‐imidazol‐2‐yl]‐1‐(2‐hydroxyethyl)piperazin‐1‐ium pyridine‐2‐carboxylate, C₁₆H₂₀ClN₄O₂⁺·C₆H₄NO₂⁻, ( 3 a )} and 4‐nitrophenylacetic acid {systematic name: 4‐[(Z )‐4‐(4‐chlorobenzylidene)‐5‐oxo‐3,4‐dihydro‐1H‐imidazol‐2‐yl]‐1‐(2‐hydroxyethyl)piperazin‐1‐ium 2‐(4‐nitrophenyl)acetate, C₁₆H₂₀ClN₄O₂⁺·C₈H₆NO₄⁻, ( 3 b )}. The crystal structures of the new salts were determined by X‐ray diffraction. In both crystal structures, the molecule of ( 3 ) is protonated at an N atom of the piperazine ring by proton transfer from the corresponding acid. The carboxylate group of picolinate engages in hydrogen bonds with three molecules of the cation of ( 3 ), whereas the carboxylate group of 4‐nitrophenylacetate engages in hydrogen bonds with only two molecules of ( 3 ). As a consequence of these interactions, different orientations of the hydroxyethyl group of ( 3 ) are observed. The crystal structures are additionally stabilized by both C—H…N [in ( 3 a )] and C—H…O [in ( 3 a ) and ( 3 b )] intermolecular interactions. The geometry of the imidazolone fragment was compared with other crystal structures possessing this moiety. The tautomer observed in the crystal structures presented here, namely 3H‐imidazol‐4(5H )‐one [systematic name: 1H‐imidazol‐5(4H )‐one], is also that most frequently observed in other structures containing this heterocycle.     

Synthesis, Crystal Structure and Properties of a New One-Dimensional 3d-4f Compound

Introduction Recently cyano bridged 3d-4f heterometallic compounds have attracted much attention because of their interesting structures and magnetic characteristics.1 The most successful and often the sole strategy for preparing these materials consists in assembling two building blocks that are transition and lanthanide metal complexes, one with terminal ligands that are able to act as bridging ligands and the other with available co-ordination sites. The [M(CN)4]2- (M=Ni, Pd, Pt),1f,2 [M…     

Synthesis and Crystal Structure of 4,7‐Diaryl‐5‐oxo‐4H‐benzo[b]pyran Derivatives

A green and convenient approach to the synthesis of a series of 4,7‐diaryl‐5‐oxo‐4H‐benzo[b]pyran derivatives from appropriate aromatic aldehydes and 5‐aryl‐1,3‐cyclohexanedione with malononitrile in the presence of dilute HCl as catalyst (30 mmol/L) is described. This method provides several advantages such as environmental friendliness, low cost, high yields, and simple work up procedure. The structures of all compounds were characterized by infrared (IR), mass spectrometry (MS), ¹H NMR, and elemental analysis. The crystal structure of trans/cis‐2‐amino‐3‐cyano‐7‐(4′‐methoxo‐phenyl)‐4‐phenyl‐5‐oxo‐4H‐benzo[b]pyran, g , was determined by single crystal X‐ray diffraction analysis. The crystal of compound g belongs to monoclinic with space group P 21/c, a = 8.477(3) nm, b = 18.948(6) nm, c = 24.915(7) nm, α = 90.00°, β = 107.388(11)°, γ= 90.00°, Z = 8, V = 3.819(2) nm³, R₁ = 0.0754, wR₂ = 0.2042.     

1,3,5‐Triamino‐1,3,5‐trideoxy‐cis‐inositol,a Ligand with a Remarkable Versatility for Metal Ions. Part XIII

The two neutral complexes [Re(CO)₃(H₋₁taci)] ( 1 ) and [ReO₃(H₋₁taci)] ( 2 ) (taci=1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol) were synthesized from the conventional Re^I and Re^VII precursors (Et₄N)₂[ReBr₃(CO)₃] and [ReO₃(OSnMe₃)]. The crystal structures of 1 and 2 , which were determined by single crystal X‐ray analysis, are virtually isomorphous. Both compounds crystallize in the orthorhombic space group Pnma, Z=4; 1 : a=14.806(3), b=8.466(2), c=9.781(2) Å, 2 : a=13.050(2), b=8.732(1), c=9.061(1) Å. In both complexes, the monodeprotonated H₋₁taci ligand is bonded to the Re center in an N,O,N‐coordination mode. The resulting molecular C_s symmetry is retained in the crystal structure and confirmed by IR spectroscopy of solid‐state samples. The observed binding mode of the ligand is discussed in terms of steric and electronic effects.     

Influence of Cl/Br substitution on the stereochemical peculiarities of copper(I) π‐complexes with the 1‐allyl‐2‐amino­pyridinium cation

By using alternating‐current electrochemical synthesis, crystals of the Cu^Iπ‐complexes bis(1‐allyl‐2‐amino­pyridinium) di‐μ‐chloro‐bis­[chloro­copper(I)], (C₈H₁₁N₂)₂[Cu₂Cl₄] or [H₂NC₅H₄NC₃H₅][CuCl₂], and bis(1‐allyl‐2‐amino­pyridinium) di‐μ‐(chloro/bromo)‐bis­[(chloro/bromo)copper(I)], (C₈H₁₁N₂)₂[Cu₂Br_2.2Cl_1.8] or [H₂NC₅H₄NC₃H₅][CuBr_1.10Cl_0.90], have been obtained and structurally investigated. In each of the isostructural (isomorphous) compounds, the distorted tetrahedral Cu environment involves three halide atoms and the C=C bond of the ligand. Both compounds reside on inversion centres, and the dimeric [Cu₂X₄·2H₂NC₅H₄NC₃H₅] units are bonded into a three‐dimensional structure by N—H⋯X hydrogen bonds. The Br content in the terminal X1 position is much higher than that in the bridged X2 site.     

Imidazole Coordinated Sandwich‐type Antimony Poly‐oxotungstates Na9[{Na(H2O)2}3{M(C3H4N2)}3(SbW9O33)2]·xH2O (M=NiII,CoII, ZnII,MnII)

The imidazole covalently coordinated sandwich‐type heteropolytungstates Na₉[{Na(H₂O)₂}₃{M(C₃H₄N₂)}₃‐ (SbW₉O₃₃)₂]·xH₂O (M=Ni^II, x=32; M=Co^II, x=32; M=Zn^II, x=33; M=Mn^II, x=34) were obtained by the reaction of Na₂WO₄·2H₂O, SbCl₃·6H₂O, NiCl₂·6H₂O [MnSO₄·H₂O, Co(NO₃)₂·6H₂O, ZnSO₄·7H₂O] and imidazole at pH≈7.5. The structure of Na₉[{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃(SbW₉O₃₃)₂]·32H₂O was determined by single crystal X‐ray diffraction. Polyanion [{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃(SbW₉O₃₃)₂}₃]^9? has approximate C_3v symmetry, imidazole coordinated six‐nuclear cluster [{Na(H₂O)₂}₃{Ni(C₃H₄N₂)}₃]⁹⁺ is encapsulated between two (α‐SbW₉O₃₃)^9?, the three rings of imidazole in the polyanion are perpendicular to the horizontal plane formed by six metals (Na‐Ni‐Na‐Ni‐Na‐Ni) in the central belt, and π‐stacking interactions exist between imidazoles of neighboring polyanions with dihedral angel of 60°. The compounds were also characterized by IR, UV‐Vis spectra, TG and DSC, and the thermal decomposition mechanism of the four compounds was suggested by TG curves.     

A New Polynuclear Copper‐Complex‐Substituted Tungstoarsenate(V)

A new polynuclear copper‐complex‐substituted dimeric tungstoarsenate(V), H₂[{Cu(2,2′‐bpy)}₈(H₂O)₂(AsW₉O₃₄)₂] · 12H₂O ( 1 ) (2,2′‐bpy = 2,2′‐bipydine), was synthesized hydrothermally and its structure was determined by single‐crystal X‐ray diffraction. The title compound has Ci symmetry and consists of two trilacunary Keggin anions [α‐AsW₉O₃₄]^9– supported by eight copper complex cations. The compound was also characterized by IR and fluorescence spectroscopy, TG analysis, and magnetic measurements. The emission spectrum of the compound in solid‐state exhibits a redshift relative to those of Na₈[A‐HAsW₉O₃₄] · 11H₂O and the free ligand 2,2′‐bpy. Magnetic measurements of the compound indicate competing ferro‐ and antiferromagnetic intramolecular coupling among the Cu^II atoms in the cluster anion.