首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 937 毫秒
1.
[(HBNPEt3)4NPEt3]3+ – a Bicyclic Penta(phosphorano)borazinium Trication [(HBNPEt3)4NPEt3]Br3 ( 1 ) has been prepared by the reaction of Me3SiNPEt3 with [HBBr2(SMe2)] in dichloromethane solution at 20°C. According to 11B‐NMR and 31P‐NMR spectroscopy and to a crystal structure determination the cation of 1 has the structure of a bicyclic penta(phosphorano)borazinium‐trication. 1 _.3CH2Cl2: Space group P212121, Z = 8, lattice dimensions at –83°C: a = 2124.8(1), b = 2307.6(1), c = 2323,1(1) pm, R1 = 0.0733.  相似文献   

2.
On the Tri(phosphorano)borazinium Monocation [H3B3(NPEt3)3Cl2]+. Crystal Structures of Me3SiNPR3 · BH3 (R = Et, Ph), [H3B3(NPEt3)3Cl1.85Br0.15]Br · CCl4, and of the Product of Hydrolysis NH4[B5O6(OH)4] · 2 H2O The crystal structures of the donor-acceptor complexes of the silylated phosphanimines with borane which are suitable as educts for the synthesis of tri(phosphorano)borazinium ions, Me3SiNPR3 · BH3 (R = Et, Ph), are described. After addition of CCl4 the reaction of Me3SiNPEt3 with HBBr2 · SMe2 in CH2Cl2 leads to the tri(phosphorano)borazinium monocation [H3B3(NPEt3)3Cl2]+, which is characterized crystallographically as [H3B3 · (NPEt3)3Cl1.85Br0.15]Br · CCl4. It complements the series of the tri(phosphorano) cations [H3B3(NPEt3)3]3+ and [H4B3(NPEt3)3]2+ by the monocation. NH4[B5O6(OH)4] · 2 H2O can be isolated as product of hydrolysis of the tri(phosphorano)borazinium ions; its crystal structure is redetermined, because in the literature it is based on a wrong space group. Me3SiNPEt3 · BH3 ( 1 ): Space group P1, Z = 4, lattice dimensions at 213 K: a = 710.9(4), b = 1465.9(3), c = 1536.0(3) pm, α = 107.05°, β = 99.40(3)°, γ = 97.41(3)°; R = 0.0740. Me3SiNPPh3 · BH3 ( 2 ): Space group P21/c, Z = 4, lattice dimensions at 203 K: a = 934.6(1), b = 1398.6(1), c = 1626.1(1) pm, β = 103.52(1)°; R = 0.0556. [H3B3(NPEt3)3Cl1.85Br0.15]Br · CCl4 ( 3 ): Space group P21/n, Z = 4, lattice dimensions at 223 K: a = 1237.9(3), b = 1214.1(3), c = 2402.4(4) pm, β = 93.52(1)°. 3 holds a B3N3 six-membered ring in a distorted boat conformation. NH4[B5O6(OH)4] · 2 H2O ( 4 ): Space group Aba2, Z = 4, lattice dimensions at 273 K: a = 1131.3(1), b = 1103.0(1), c = 923.0(1) pm; R = 0.0564.  相似文献   

3.
Colourless, lath‐shaped single crystals of Cs2[B12I12] · 2 CH3CN (monoclinic, C2/m; a = 1550.3(2), b = 1273.2(1), c = 1051.5(1) pm, β = 120.97(1)°; Z = 2) are obtained by the reaction of Cs2[B12H12] with an excess of I2 and ICl (molar ratio: 1 : 2) in methylene iodide (CH2I2) at 180 °C (8 h) and recrystallization of the crude product from acetonitrile (CH3CN). The crystal structure contains quasi‐icosahedral [B12I12]2– anions (d(B–B) = 176–182 pm, d(B–I) = 211–218 pm) which arrange in a cubic closest‐packed fashion. All octahedral interstices are filled with centrosymmetric dimer‐cations {[Cs(N≡C–CH3)]2}2+ containing a diamond‐shaped four‐membered (Cs–N–Cs–N) ring of Cs+ cations and nitrogen atoms of the solvating acetonitrile molecules (d(Cs–N) = 321 pm, 2 ×). The cesium cations themselves actually reside in the distorted tetrahedral voids of the cubic [B12I12]2– packing (d(Cs–I) = 402–461 pm, 10 ×) if one ignores the solvent particles.  相似文献   

4.
The Syntheses and Vibrational Spectra of the Homoleptic Metal Acetonitrile Cations [Au(NCCH3)2]+, [Pd(NCCH3)4]2+, [Pt(NCCH3)4]2+, and the Adduct CH3CN · SbF5. The Crystal and Molecular Structures of [M(NCCH3)4][SbF6]2 · CH3CN, M = Pd or Pt Solvolyses of the homoleptic metal carbonyl salts [M(CO)4][Sb2F11]2, M = Pd or Pt, in acetonitrile leads at 50 °C both to complete ligand exchange for the cations as well as to a conversion of the di-octahedral anion [Sb2F11] into [SbF6] and the molecular adduct CH3CN · SbF5 according to: [M(CO)4][Sb2F11]2 + 7 CH3CN → [M(NCCH3)4][SbF6]2 · CH3CN + 2 CH3CN · SbF5 + 4 CO M = Pd, Pt The monosolvated [M(NCCH3)4][SbF6]2 · CH3CN are obtained as single crystals from solution and are structurally characterized by single crystal x-ray diffraction. Both salts are isostructural. The cations are square planar but the N–C–C-sceletial groups of the ligands depart slightly from linearity. The new acetonitrile complexes as well as [Au(NCCH3)2][SbF6] and the adduct CH3CN · SbF5 are completely characterized by vibrational spectroscopy.  相似文献   

5.
Cationic lanthanide complexes of the type [Ln(CH3CN)9]3+[(AlCl4)3]3–·CH3CN (Ln = Pr, Nd, Sm, Gd, Er, Yb, Y) served as effective catalysts for the intramolecular hydroalkoxylation/cyclization of unactivated alkenols to yield the cyclic ethers with Markovnikov regioselectivity under mild conditions. Novel cationic complexes, [AlCl(CH3CN)5]2+[(AlCl4)2]2–·CH3CN and [Nd(CH3CN)9]3+[(FeCl4)3]3–·CH3CN, were synthesized and evaluated for the intramolecular hydroalkoxylation/cyclization of unactivated alkenols for comparison. The active sequence of [Nd(CH3CN)9]3+[(FeCl4)3]3–·CH3CN < [AlCl(CH3CN)5]2+[(AlCl4)2]2–·CH3CN < [Nd(CH3CN)9]3+[(AlCl4)3]3–·CH3CN observed indicated that both the cation and anion have great influence on the activity. Comparative study on the activity of AlCl3 and its cationic complex [AlCl(CH3CN)5]2+[(AlCl4)2]2–·CH3CN revealed the formation of the cationic Al center enhanced the activity greatly. The 1H NMR studies indicated the activation of hydroxyl and olefin by the cationic Ln3+ center were involved in the reaction pathways.  相似文献   

6.
The osmium nitride complex [OsVI(NH3)4N]3+ undergoes a one-electron reduction in acetonitrile to give [OsV(N)(NH3)4]2+, which further reacts by nitride coupling to give the μ-dinitrogen osmium complex [(CH3CN)(NH3)4OsII(N2)OsII(NH3)4(CH3CN)]4+. The formation of the μ-dinitrogen osmium complex is promoted by the presence of perchlorate anion, which causes the deposition of [(CH3CN)(NH3)4OsII(N2)OsII(NH3)4(CH3CN)](ClO4)4 on the electrode surface upon repetitive voltammetric scans.  相似文献   

7.
Yanan Zhu  Zhigang Yao  Fan Xu 《Tetrahedron》2018,74(31):4211-4219
Cationic lanthanide complexes [Ln(CH3CN)9]3+[(AlCl4)3]3–·CH3CN served as efficient catalysts for the tandem Friedel–Crafts alkylation/ketalization reaction of 2-hydroxychalcones with naphthols/substituted phenols to produce diaryl-fused 2,8-dioxabicyclo[3.3.1]nonanes in moderate to high yields. The high catalytic efficiency of the cationic lanthanide complex [Yb(CH3CN)9]3+[(AlCl4)3]3–·CH3CN compared with that of YbCl3 can be attributed to the increased Lewis acidity of the Yb species as a result of cation formation.  相似文献   

8.
Crystal Structure and Vibrational Spectrum of (H2NPPh3)2[SnCl6]·2CH3CN Single crystals of (H2NPPh3)2[SnCl6]·2CH3CN ( 1 ) were obtained by oxidative addition of tin(II) chloride with N‐chloro‐triphenylphosphanimine in acetonitrile in the presence of water. 1 is characterized by IR and Raman spectroscopy as well as by a single crystal structure determination: Space group , Z = 2, lattice dimensions at 193 K: a = 1029.6(1), b = 1441.0(2), c = 1446.1(2) pm, α = 90.91(1)°, β = 92.21(1)°, γ = 92.98(1)°, R1 = 0.0332. 1 forms an ionic structure with two different site positions of the [SnCl6]2? ions. One of them is surrounded by four N‐hydrogen atoms of four (H2NPPh3)+ ions, four CH3CN molecules form N–H···N≡C–CH3 contacts with the other four N‐hydrogen atoms of the cations. Thus, 1 can be written as [(H2NPPh3)4(CH3CN)4(SnCl6)]2+[SnCl6]2?.  相似文献   

9.
Structure and Properties of the Methyltetrafluorophosphate Anion, [CH3PF5] Methyltetrafluorphosphorane reacts with the fluorides NaF, KF, CsF, and (CH3)4NF with formation of the corresponding methylpentafluorophosphates. In case of the K and Cs salts K[CH3PF5] · CH3CN and Cs[CH3PF5] · CH3CN, respectively, are formed using acetonitrile as solvent. The salts are characterized by NMR, IR and Raman spectroscopy. The vibrational frequencies are compared with ab initio calculated data (RHF/6‐31+G*). The RHF/6‐31+G* calculation yields for the almost octahedral anion bond distances of d(PFeq) = 163.7 pm, d(PFax) = 162.0 pm, and d(PC) = 184.8 pm.  相似文献   

10.
Bis(triphenylphosphoranylidene)ammonium iodide (PPN+I?) forms a 2:3 complex with TCNQ [(PPN)2(TCNQ)3(CH3CN)2] that provides an example of a TCNQ complex containing acetonitrile in the crystal lattice; the material is a semi-conductor with trimerised TCNQ stacks.  相似文献   

11.
The Crystal Structures of (NH4)2[ReCl6], [ReCl2(CH3CN)4]2[ReCl6] · 2CH3CN and [ReCl4(18)(Crown-6)] Brown single crystals of (NH4)2[ReCl6] are formed by the reaction of NH4Cl with ReCl5 in a suspension of diethylether. [ReCl2(CH3CN)4]2[ReCl6] · 2CH3CN crystallizes as brown crystal plates from a solution of ReCl5 in acetonitrile. Lustrous green single crystals of [ReCl4(18-crown-6)] are obtained by the reaction of 18-crown-6 with ReCl5 in a dichloromethane suspension. All rhenium compounds are characterized by IR spectroscopy and by crystal structure determinations. (NH4)2[ReCl6]: Space group Fm3 m, Z = 4, 75 observed unique reflections, R = 0.01. Lattice constant at ?70°C: a = 989.0(1) pm. The compound crystallizes in the (NH4)2[PtCl6] type, the Re? Cl distance is 235.5(1) pm. [ReCl2(CH3CN)4]2[ReCl6] · 2CH3CN: Space group P1, Z = 1, 2459 observed unique reflections, R = 0.12. Lattice dimensions at ?60°C: a = 859.0(1), b = 974.2(7), c = 1287.3(7) pm, α = 102.69(5)°, b? = 105.24(7)°, γ = 102.25(8)°. The structure consists of two symmetry-independent [ReCl2(CH3CN)4]+ ions with trans chlorine atoms, [ReCl6]2? ions, and included acetonitrile molecules. In the cations the Re? Cl bond lengths are 233 pm in average, in the anion they are 235 pm in average. [ReCl4(18-crown-6)]: Space group P21/n, Z = 4, 3 633 observed unique reflections, R = 0.06. Lattice dimensions at ?70°C: a = 1040.2(4), b = 1794.7(5), c = 1090.0(5) pm, b? = 108.91(4)°. The compound forms a molecular structure, in which the rhenium atom is octahedrally coordinated by the four chlorine atoms and by two oxygen atoms of the crown ether molecule.  相似文献   

12.
A series of the octapalladium chains supported by meso-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2 (meso-dpmppm) ligands, [Pd8(meso-dpmppm)4(L)2](BF4)4 (L=none ( 1 ), solvents: CH3CN ( 2 a ), dmf ( 2 b ), dmso ( 2 c ), RN≡C: R=Xyl ( 3 a ), Mes ( 3 b ), Dip ( 3 c ), tBu ( 3 d ), Cy ( 3 e ), CH3(CH2)7 ( 3 f ), CH3(CH2)11 ( 3 g ), CH3(CH2)17 ( 3 h )) and [Pd8(meso-dpmppm)4(X)2](BF4)2 (X=Cl ( 4 a ), N3 ( 4 b ), CN ( 4 c ), SCN ( 4 d )), were synthesized by using 2 a as a stable good precursor, and characterized by spectroscopic (IR, 1H and 31P NMR, UV-vis-NIR, ESI-MS) measurements and X-ray crystallographic analyses (for 1 , 2 a , b , 3 a , b , e , f , 4 a – d ). On the basis of DFT calculations on the X-ray determined structure of 2 b ( [2b-Pd8]4+ ) and the optimized models [Pd8(meso-Ph2PCH2P(H)CH2P(H)CH2PH2)4(CH3CN)2]4+ ( [Pd8Ph8]4+ ) and [Pd8(meso-H2PCH2P(H)CH2P(H)CH2PH2)4(CH3CN)2]4+ ( [Pd8H8]4+ ), with and without empirically calculating dispersion force stabilization energy (B3LYP-D3, B3LYP), the formation energy between the two Pd4 fragments is assumed to involve mainly noncovalent interactions (ca. −70 kcal/mol) with four sets of interligand C−H/π interactions and Pd⋅⋅⋅Pd metallophilic one, while electron shared covalent interactions are almost canceled out within the Pd8 chain. All the compounds isolated are stable in solution and exhibit characteristic absorption at ∼900 nm, which is assignable to a spin allowed HOMO to LUMO transition, and shows temperature dependent intensity change with variable absorption coefficients presumably due to coupling with some thermal vibrations. The structures and electronic states of the Pd8 chains are found finely tunable by varying the terminal capping ligands. In particular, theoretical calculations elucidated that the HOMO-LUMO energy gap is systematically related to the central Pd−Pd distance (2.7319(6)–2.7575(6) Å) by two ways with neutral ligands L ( 1 , 2 , 3 ) and with anionic ligands X ( 4 ), which are reflected on the NIR absorption energy of 867–954 nm. The isocyanide terminated Pd8 complexes ( 3 ) further reacted with excess of RNC (6 eq) to afford the Pd4 complexes, [Pd4(meso-dpmppm)2(RNC)2](BF4)2 ( 13 ), and the cyclic voltammograms of 2 a (L=CH3CN), 3 , and 13 (R=Xyl, Mes, tBu, Cy) demonstrated wide range redox behaviors from 2{Pd4}4+ to 2{Pd4}0 through 2{Pd4}2+↔{Pd8}4+, {Pd8}3+, and {Pd8}2+ strings. The oxidized complexes, [Pd4(meso-dpmppm)2(RNC)3](BF4)4 ( 16 ), were characterized by X-ray analyses, and the two-electron reduced chain of [Pd8(meso-dpmppm)4](BF4)2 ( 7 ) was analyzed by spectroscopic and electrochemical techniques and DFT calculations. Reactions of 2 a with 1 equiv. of aromatic linear bisisocyanide (BI) in CH2Cl2 deposited insoluble coordination polymers, {[Pd8(meso-dpmppm)4(BI)](BF4)4}n ( 5 ), and interestingly, they were soluble in acetonitrile, 31P{1H} and 1H DOSY NMR spectra as well as SAXS curves suggesting that the coordination polymers may exist in acetonitrile as dynamically 1D self-assembled coordination polymers comprising ca. 50 units of the Pd8 rod averaged within the timescale.  相似文献   

13.
Single crystals of [Be33‐O)3(MeCN)6{Be(MeCN)3}3](I)6·4CH3CN ( 1 ·4CH3CN) were obtained in low yield by the reaction of beryllium powder with iodine in acetonitrile suspension, which probably result from traces of beryllium oxide containing the applied beryllium metal. The compound 1 ·4CH3CN forms moisture sensitive, colourless crystal needles, which were characterized by IR spectroscopy and X‐ray diffraction (Space group Pnma, Z = 4, lattice dimensions at 100(2) K: a = 2317.4(1), b = 2491.4(1), c = 1190.6(1) pm, R1 = 0.0315). The hexaiodide complex cation 1 6+consists of a cyclo‐Be3O3 core with slightly distorted chair conformation, stabilized by coordination of two acetonitrile ligands at each of the beryllium atoms and by a {Be(CH3CN)3}2+ cation at each of the oxygen atoms. This unique coordination behaviour results in coplanar OBe3 units with short Be–O distances of 155.0 pm and 153.6 pm on average of bond lengths within the cyclo‐Be3O3 unit and of the peripheric BeO bonds, respectively. Exposure of compound 1 ·4CH3CN to moist air leads to small orange crystal plates of [Be(H2O)4]I2·2CH3CN ( 3 ·2CH3CN). According to the crystal structure determination (Space group C2/c, Z = 4, lattice dimensions at 100(2) K: a = 1220.7(1), b = 735.0(1), c = 1608.5(1) pm, β = 97.97(1)°, R1 = 0.0394), all hydrogen atoms of the dication [Be(H2O)4]2+ are involved to form O–H ··· N and O–H ··· I hydrogen bonds with the acetonitrile molecules and the iodide ions, respectively. Quantum chemical calculations (B3LYP/6‐311+G**) at the model [Be33‐O)3(HCN)6{Be(HCN)3}3]6+ show that chair and boat conformation are stable and that the distorted chair conformation is stabilized by packing effects.  相似文献   

14.
Phosphorane Iminato Complexes of Antimony. The Crystal Structures of [Sb2Cl5(NPMe3)2][SbCl6] · CH3CN and [SbCl(NPPh3)]2[SbCl6]2 · 6 CH3CN The title compounds are formed by reaction of antimony pentachloride in acetonitrile solution with the phosphorane iminato complexes SbCl2(NPMe3) and SbCl2(NPPh3), respectively, which themselves are synthesized by reaction of antimony trichloride with Me3SiNPR3 (R = Me, Ph). The complexionic compounds are characterized by 121Sb Mössbauer spectroscopy and by crystal structure determinations. [Sb2Cl5(NPMe3)2][SbCl6] · CH3CN: Space group P41, Z = 4, 3 698 observed unique reflections, R = 0.022. Lattice dimensions at ?60°C: a = b = 1 056.0(1), c = 2 709.6(2) pm. The structure consists of SbCl6? ions and cations [Sb2Cl5(NPMe3)2(CH3CN)]+, in which one SbIII atom and one SbV atom are bridged by the N atoms of the phosphorane iminato ligands. [SbCl(NPPh3)]2[SbCl6]2 · 6 CH3CN: Space group P1 , Z = 2, 5 958 observed unique reflections, R = 0.033. Lattice dimensions at ?60°C: a = 989.4(11), b = 1 273(1), c = 1 396(1) pm, α = 78.33(7), β = 77.27(8)°, γ = 86.62(8)°. The structure consists of SbCl6? ions and centrosymmetric cations [SbCl(NPPh3)(CH3CN)2]22+, in which the antimony atoms are bridged by the N atoms of the phosphorane iminato ligands.  相似文献   

15.
A redox reaction that occurs in the [Cu2B10H10]/Phen system in CH3CN/DMSO and CH3CN/DMF in air yields a Cu(II) binuclear complex, [(Phen)2Cu(CO3)Cu(Phen)2]2+. The [Cu2(Phen)4(μ-CO3)]B10H10 · 2.5DMSO · 2H2O (I) and [Cu2(Phen)4(μ-CO3)]B10H10 · 4DMF (II) compounds have been isolated and studied by X-ray crystallography at 150 K and EPR at 295 K. Their magnetic properties have been studied in the range 300–2 K. In the cations of both compounds, the bridging CO 3 2? group is bidentately coordinated to two Cu atoms. The cations in I and II have different spatial orientations of the Cu-O bonds: anti-syn and anti-anti, respectively. Compound I has weak magnetic interactions caused by a short Cu…Cu distance (4.441 Å) in the dimer. No exchange coupling is observed in II.  相似文献   

16.
Two novel complexes of CuCN were characterized by using a single-crystal X-ray diffraction technique and Raman spectroscopy. In the structure of 2CuCN·DMSO ligand molecule demonstrates unique bridging mode, being bound to two CuI centers via oxygen and sulfur atoms. The bridging role of both CN groups and DMSO molecules results in the formation of (CuCN·DMSO)n framework. Along the channels of the network are running infinite zig-zag (CuCN)n chains, which are bound to the framework by elongated Cu…(CN) bonds. A mixed-valence [CuII(DMSO)6][CuI 6(CN)8] compound is composed of 3-D [CuI 6(CN)8]n anionic framework and located in the channels of partially disordered [CuII(DMSO)6]2+ cations.  相似文献   

17.
The use of the [FeIII(AA)(CN)4]? complex anion as metalloligand towards the preformed [CuII(valpn)LnIII]3+ or [NiII(valpn)LnIII]3+ heterometallic complex cations (AA=2,2′‐bipyridine (bipy) and 1,10‐phenathroline (phen); H2valpn=1,3‐propanediyl‐bis(2‐iminomethylene‐6‐methoxyphenol)) allowed the preparation of two families of heterotrimetallic complexes: three isostructural 1D coordination polymers of general formula {[CuII(valpn)LnIII(H2O)3(μ‐NC)2FeIII(phen)(CN)2 {(μ‐NC)FeIII(phen)(CN)3}]NO3 ? 7 H2O}n (Ln=Gd ( 1 ), Tb ( 2 ), and Dy ( 3 )) and the trinuclear complex [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3] ? NO3 ? H2O ? CH3CN ( 4 ) were obtained with the [CuII(valpn)LnIII]3+ assembling unit, whereas three isostructural heterotrimetallic 2D networks, {[NiII(valpn)LnIII(ONO2)2(H2O)(μ‐NC)3FeIII(bipy)(CN)] ? 2 H2O ? 2 CH3CN}n (Ln=Gd ( 5 ), Tb ( 6 ), and Dy ( 7 )) resulted with the related [NiII(valpn)LnIII]3+ precursor. The crystal structure of compound 4 consists of discrete heterotrimetallic complex cations, [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3]+, nitrate counterions, and non‐coordinate water and acetonitrile molecules. The heteroleptic {FeIII(bipy)(CN)4} moiety in 5 – 7 acts as a tris‐monodentate ligand towards three {NiII(valpn)LnIII} binuclear nodes leading to heterotrimetallic 2D networks. The ferromagnetic interaction through the diphenoxo bridge in the CuII?LnIII ( 1 – 3 ) and NiII?LnIII ( 5 – 7 ) units, as well as through the single cyanide bridge between the FeIII and either NiII ( 5 – 7 ) or CuII ( 4 ) account for the overall ferromagnetic behavior observed in 1 – 7 . DFT‐type calculations were performed to substantiate the magnetic interactions in 1 , 4 , and 5 . Interestingly, compound 6 exhibits slow relaxation of the magnetization with maxima of the out‐of‐phase ac signals below 4.0 K in the lack of a dc field, the values of the pre‐exponential factor (τo) and energy barrier (Ea) through the Arrhenius equation being 2.0×10?12 s and 29.1 cm?1, respectively. In the case of 7 , the ferromagnetic interactions through the double phenoxo (NiII–DyIII) and single cyanide (FeIII–NiII) pathways are masked by the depopulation of the Stark levels of the DyIII ion, this feature most likely accounting for the continuous decrease of χM T upon cooling observed for this last compound.  相似文献   

18.
The deep blue, paramagnetic Cs2[TcII(NO)F5] is formed during reactions of pertechnetate, acetohydroxamic acid, and CsF in aqueous HF. A reaction of Cs2[Tc(NO)F5] with BF3 · MeOH in acetonitrile gives yellow blocks of the fluorido‐bridged dimer [{TcI(NO)(CH3CN)4}2F](BF4)3. The compound is stable as solid and in acetonitrile solutions. The complex cation contains a bent μ‐F ligand and two linear nitrosyl groups.  相似文献   

19.
Pentaquadrupole (QqQqQ) mass spectrometry is used to explore the abilities of gaseous SFn+ (n = 1–5) ions to form adducts and dimers with three π-electron rich molecules—benzene, acetonitrile, and pyridine, whereas ab initio calculations estimate most feasible structures, bond dissociation energies (BDEs), and reaction enthalpies of the observed products. With benzene, SF+ reacts by net H-by-SF replacement. As suggested by the calculations, this novel benzene reaction forms ionized benzenesulfenyl fluoride, C6H5–SF, via a Wheland-type intermediate that spontaneously loses a H atom. SF3+ forms a rare, loosely bonded π complex with benzene, [Bz ⋯ SF3]+, which is stable toward both H and HF loss. No dimer, Bz2SF3+, is formed. According to calculations, an unsymmetrically bonded, π-coordinated Bz2SF3+ dimer exists, i.e. (Bz–SF3 ⋯ Bz)+, but its formation from [Bz ⋯ SF3]+ is endothermic; hence, thermodynamically unfavorable. With acetonitrile, SF2, SF3+, and SF5+ form both adducts and dimers. CH3–C·N–SF2+ (a new distonic ion) and CH3CN–SF5+ are covalently bonded, but CH3CN ⋯ SF3+ is loosely bonded. The binding natures of the acetonitrile adducts are reflected in the dimers; [CH3CN–SF2 ⋯ NCCH3] and [CH3CN–SF5 ⋯ NCCH3]+ are unsymmetrically bonded, whereas [CH3CN ⋯ SF3 ⋯ NCCH3]+ is symmetrically and loosely bonded. Such dimers as [CH3CN ⋯ SF3 ⋯ NCCH3]+ are ideal for measurements of ion affinity via the Cooks’ kinetic method. With pyridine, only SF3+ forms adduct and dimer. Py–SF3+ is covalently bonded through nitrogen; [Py ⋯ SF3 ⋯ Py]+ is loosely but unsymmetrically bonded. The unsymmetric 2.28 and 2.44 Å long N–S bonds in [Py ⋯ SF3 ⋯ Py]+, which are expected to rapidly interconvert, result likely from steric hindrance that forces orthogonal alignment of the two pyridine rings. Most observed adducts and dimers display relatively high BDEs, i.e. they are formed in thermodynamically favorable reactions. The extents of dissociation of the adducts and dimers observed in MS3 experiments reflect the structures and BDEs predicted by the calculations.  相似文献   

20.
The new Lewis acid Al(OTeF5)3 and its acetonitrile adduct CH3CN→Al(OTeF5)3 were obtained by a simple one-step synthesis in batches of up to 15 g. Al(OTeF5)3 and the adduct were characterized by vibrational spectroscopy (IR, Raman) and quantum-chemical calculations. Furthermore, five different salts of the new weakly coordinating anion [Al(OTeF5)4] were prepared in a two-step procedure. [Ph4P][Al(OTeF5)4], Cs[Al(OTeF5)4], [Ph3C][Al(OTeF5)4], as well as the protonated benzene derivatives [C9H13][Al(OTeF5)4] and [C6H7][Al(OTeF5)4] were characterized by low-temperature single-crystal X-ray diffraction and NMR spectroscopy. Arenium salts have rarely been characterized in the solid state and were synthesized in this work in a simplified fashion.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号