S4N3⊕[ReCl4(NSCl)2]?. Synthesis and Crystal Structure S4N3⊕[ReCl4(NSCl)2]? is formed as a byproduct in the reaction of Re2(CO)10 with excess trithiazyl chloride. The compound is characterized by a crystal structure analysis by X-ray methods. S4N3[ReCl4(NSCl)2] crystallizes in the noncentrosymmetric space group P212121 with four formula units per unit cell and the lattice dimensions a = 980, b = 1205, c = 1362 pm (2376 observed, independent reflexions; R = 0.076). The compound consists of the well known cyclic planar S4N3⊕-cations and anions [ReCl4(NSCl)2]?, in which the rhenium atom is coordinated octahedral by four Cl atoms and two cis-positioned NSCl ligands. The mean Re? N and N? S bond lengths (177 pm and 158 pm) correspond to double bonds. The bond lengths and angles are much like in the structure of AsPh4[ReCl4(NSCl)2]; however the chlorine atoms of the NSCl ligands are turned to each other. 相似文献
Complexes of Rhenium with Planar ReN2S2 Rings. Syntheses and Crystal Structures of AsPh4[ReCl4(N2S2)] and PPh4[ReBr4(N2S2)] The complex [ReCl4(N2S2)]? can be obtained as PPh4⊕ or AsPh4⊕ salt by the action of S(NSiMe3)2 and of diphenylacetylene, respectively, on the chlorothionitrene complex [ReCl4(NSCl)2]?. Another method of synthesis is the reaction of [ReCl3(NSCl)2(POCl3)] with SbPh3. [ReBr3(N2S2)]2 is obtained from excess Me3SiBr and [ReCl3(NSCl)2(POCl3)]. The anionic complex [ReBr4(N2S2)]? forms from either [ReCl4(NSCl)2]? or [ReCl4(N2S2)]? with Me3SiBr. All compounds are black, diamagnetic, and sensitive to moisture; the PPh4⊕ and AsPh4⊕ salts are soluble in CH2Cl2 and CH2Br2. The IR spectra are reported. The crystal structures of AsPh,4[ReCl4(N2S2)] and PPh4[ReBr4(N2S2)] were determined by X-ray diffraction. AsPh4[ReCl4(N2S2)]: space group P2/n, Z = 2, a = 1244.5, b = 1429.3, c = 791.1 pm, γ = 96.89° (1715 observed reflexions, R = 0.082). PPh4[ReBr4[ReBr4(N2S2)]: space group P21/n, Z = 4, a = 961.7, b = 1397.4, c = 2205.7 pm, β = 102.10° (1787 observed reflexions, R = 0.073). In both compounds the [ReX4(N2S2)]? anions have the same type of structure, the Re atoms forming part of planar ReN2S2 rings; the bond lengths are ReN 177 pm, NS 152 pm, and SS 259 for the chloro compound and ReN 184 pm, NS 153 pm, and SS 264 pm for the bromo compound. In AsPh4[ReCl4(N2S2)] the cations are stacked to form columns in the c-direction; in PPh4[ReBr4(N2S2)], there is considerable distortion form this packing principle. 相似文献
(PPh4)2[OsCl3(NO) (SnCl3)2]; Preparation, I.R. Spectrum, and Crystal Structure (P(C6H5)4)2[OsCl3(NO)(SnCl3)2] yields from the reaction of OsCl3(NO) with PPh4-[SnCl3] in dichloro methane forming red crystals. The complex crystallizes monoclinic in the space group C2/c with four formula units per unit cell. The crystal structure was determined by aid of X-ray diffraction data (2261 independent, observed reflexions, R = 4.9%). The cell parameters are a = 1369, b = 1989, c = 2088 pm, β = 99.54°. The structure consists of tetraphenyl phosphonium cations and [OsCl3(NO)(SnCl3)2]2?-anions. In the anion the osmium is coordinated octahedrally by three chlorine atoms (mean bond length r Os? Cl 238 pm), two SnCl3 groups in transposition to each other (r Os? Sn 265 pm) and the N-atom of the covalently bonded nitrosyl ligand (r Os? N 173 pm). The i.r. spectrum of the anion is reported and assigned. 相似文献
Cyclo-S2N2 Bridged Chlorothionitrene Complexes of Molybdenum and Tungsten. Crystal Structure of μ-(S2N2)[MoCl4(NSCl)]2 Molybdenum pentachloride reacts with (NSCl)3 in CH2Cl2 suspension giving a product mixture from which the complex μ-(S2N2)[MoCl4(NSCl)]2 can be extracted with CH2Cl2. It forms black crystals, whereas the corresponding tungsten compound forms copper-red crystals. μ-(S2N2)[WCl4(NSCl)]2 is obtained by abstraction of SCl2 and chlorine from N(SCl)2[WCl5(NSCl)], which can be obtained from WCl6 and N2S3Cl2. According to their i.r. spectra both complexes μ-(S2N2)[MCl4(NSCl)]2 have the same molecular structure. The crystal structure of μ-(S2N2)[MoCl4(NSCl)]2 was determined and refined with X-ray diffraction data (1851 reflexions, R = 0.019). It crystallizes in the triclinic space group P1 with two molecules per unit cell. The lattice constants are a = 685, b = 735, c = 963 pm, α = 76.6°, β = 80.9°, γ = 87.0°. μ-(S2N2)[MoCl4(NSCl)]2 forms centrosymmetric molecules in which the Mo atoms of the MoCl4(NSCl) units are linked via the N atoms of a planar N2S2 ring. The Mo atoms have coordination number 6, having the N atom of the chlorothionitrene ligand Mo in trans position to the N atom of the S2N2 ring. 相似文献
Thionitrosyl Complexes of Osmium. Crystal Structure of AsPh4[OsCl4(NS)2Cl] The reaction of osmium pentachloride with trithiazyl chloride (NSCl)3 yields the thiazylchloride complex [OsCl4(NSCl)2], from which the thionitrosyl complex AsPh4[OsCl4(NS)2Cl] is obtained by reaction with AsPh4Cl in CH2Cl2. From this, the neutral thionitrosyl complex [OsCl4(NS)2] forms by chloride abstraction with gallium trichloride. The crystal structure of AsPh4[OsCl4(NS)2Cl] was determined and refined with the aid of X-ray diffraction data (R = 0.033, 2161 reflexions). It crystallizes in the monoclinic space group P21/c with four formula units per unit cell. The lattice constants are a = 1735, b = 1058, c = 1578 pm and β 95.64°. In the [OsCl4(NS)2Cl]? ion the osmium is octahedrally coordinated by four Cl atoms and two NS groups in a cis arrangement. The NS groups are essentially linear with the bond lengths Os?N 184 pm and N?S 146 pm. Loosely attached to one of the S atoms there is a Cl atom (S? Cl distance 228 pm); in the crystal it statistically belongs to both S atoms with an occupation probability of one half, and it cannot be decided whether there is a dynamical fluctuation between the S atoms or a static positional disorder. However, according to the i.r. spectrum the dynamical model seems more probable. 相似文献
N(SCl)2⊕ [MoCl5(NSCl)]?, a Chlorothionitrene Complex of Molybdenum (VI) . The title compound is formed together with MoCl3(N3S2) by the reaction of MoCl4 or MoCl5 with (NSCl)3 in CH2Cl2. The black, crystalline compound was characterized by its i.r. spectrum and an X-ray crystal structure determination. N(SCl)2⊕[MoCl5(NSCl)]? crystallizes in the monoclinic space group P21/n with four formula units per unit cell. The lattice constants are a = 716.3, b = 1627.4, c = 1178.9 pm and β = 100.90°. The [MoCl5(NSCl)]? ion posseses an almost linear Mo = N = S grouping with bond lengths that can be interpreted as double bonds. Crystal data for AsPh4[MoCl5(NSCl)] are reported. 相似文献
(PPh3Me)2[{MoCl4(NO)}2(μ-S2 N2)]; Synthesis, I.R. Spectrum, and Crystal Structure The title compound is prepared by the reaction of (PPh3Me)2[MoCl3(NO)2]2 with trithiazyl chloride in CH2Cl2 solution. It forms yellow, only slightly moisture sensitive crystals, which are characterized by their IR spectrum as well as by an X-ray structure determination. (PPh3Me)2[{MoCl4(NO)}2 (μ-S2N2)] crystallizes triclinic in the space group P1 with one formula unit in the unit cell (5952 independent, observed reflexions, R = 0.045). The lattice dimensions are at 20°C: a = 1021, b = 1143, c = 1243, pm; α = 64,15°, β = 68.24°, γ = 80.85°. The compound consists of PPh3Me⊕ cations and anions [{MoCl4(NO)}2(μ-S2N2)]2?, in which the molybdenum atoms are bridged by the N-atoms of the planar S2N2 ring. In the trans-positions of these N-atoms the linear nitrosyl groups are coordinated via Mo ? N ? O . 相似文献
Preparation, Crystal Structure, and Normal Coordinate Analysis of Linkage Isomeric Pentachloroiodoselenocyanatoosmates(IV). Crystal Structure of trans‐(PPh4)2[OsCl4I(NCSe)] By treatment of the solution of (n‐Bu4N)2[OsCl5I] in dichloromethane with suspended Pb(SeCN)2 the linkage isomers trans‐(n‐Bu4N)2[OsCl4I(NCSe)] ( 1 ) and trans‐(n‐Bu4N)2[OsCl4I(SeCN)] ( 2 ) are formed, which have been separated by ion exchange chromatography on diethylaminoethyl cellulose. The X‐Ray structure determination on a single crystal of trans‐(PPh4)2[OsCl4I(NCSe)] (triclinic, space group P1¯, a = 10.8950(13), b = 11.076(2), c = 20.980(2)Å, α = 96.940(10), β = 98.747(9), γ = 104.419(11)°, Z = 2) reveals, that the nearly linear selenocyanate group in trans position to the iodine atom is coordinated with the Os‐N‐C angle of 171.1°. Based on the molecular parameters of the X‐ray determination ( 1 ) and estimated data ( 2 ) the IR and Raman spectra of both linkage isomers are assigned by normal coordinate analysis. The valence force constants are fd(OsN) = 1.70 und fd(OsSe) = 1.15 mdyn/Å. 相似文献
Synthesis and Crystal Structure of Tetraphenylphosphonium Aqua-bis(tetrasulfido)thionitrosyl Osmate, PPh4[Os(NS)(S4)2(H2O)] PPh4[Os(NS)(S4)2(H2O)] has been prepared as redbrown crystals by reacting PPh4[OsNCl4] with a solution of excess disodium tetrasulfide in dimethylformamide/H2O and characterized by IR spectroscopy and by a crystal structure determination. Space group P21/n, Z = 4, structure solution with 4162 independent reflections, R = 0.059 for reflections with I > 2σ(I). Lattice dimensions at ?40°C: a = 1138.9(5), b = 1301.4(4), c = 2092.7(7) pm, β = 104.74(3)º. Os? N, Os? O, and Os? S distances are 175.2(12), 219.8(12), and 237.5(4)?239.1(4) pm, respectively. The Os?N?S moiety is approximately linear, with an OsNS angle of 171.2(7)º. 相似文献
Chlorothionitrene Complexes of Tungsten. Crystal Structure of [WCl4(NSCl)]2 Tungsten hexachloride reacts with trithiazyl chloride, (NSCl)3, yielding the chlorothionitrene complex [WCl4(NSCl)]2, from which AsPh4[WCl5(NSCl)] can be obtained by reaction with AsPh4Cl. Both complexes are characterized by their i.r. spectra. The crystal structure of [WCl4(NSCl)]2 was determined and refined with X-ray diffraction data (1059 reflexes, R = 0.055). It crystallizes in the monoclinic space group P21/n with the lattice constants a = 1523, b = 904, c = 583 pm and β = 91.35°. In the unit cell there are two centrosymmetric [WCl4(NSCl)]2 molecules in which the W atoms are linked via two chloro bridges; short and long W? Cl distances (244 and 265 pm) alternate in the W2Cl2 ring, the NSCl groups are found in the trans positions to the longer W? Cl bonds. The WNS bond angle (175°) and short bond distances correspond to a formulation . 相似文献
Synthesis and Crystal Structure of (AsPh4)2[Cl5WNSNWCl5] . The chlorothionitrene complex [WCl4(NSCl)]2 reacts with excess tetraphenylarsonium chloride via the intermediate AsPh4[Cl5W(NSCl)] to yield the title compound. This was characterized by its i.r. spectrum and an X-ray crystal structure determination (4078 reflexions uncluding Friedel pairs, R = 0.059). (AsPh4)2[Cl5WNSNWCl5] crystallizes in the monoclinic system, a = 1110.5, b = 1714.6, c = 1521.7 pm, β = 107.24°, Z = 2. The space group is either P21/n with anions statistically disordered in two different positions or Pn with an apparent higher symmetry due to the presence of inversion twins. Bond distances and angles correspond to the formula 相似文献
(PPh4)2[Cl2Re(N3S2)(μ‐NSN)(μ‐N≡ReCl3)]2 – a Rhenium(VII) Complex with a Nitrido, a Dinitridosulfato(II), and a Rhena‐3,5‐dithia‐2,4,6‐triazino Function The title compound has been prepared from PPh4[ReVIICl4(NSCl)2] with N(SiMe3)3 in dichloromethane solution to give red‐brown single crystals, which were suitable for a crystal structure determination. As a by‐product PPh4[ReNCl4] is formed. (PPh4)2[Cl2ReVII(N3S2)(μ‐NSN)(μ‐N≡ReVIICl3)]2 ( 1 ): Space group P21/c, Z = 2, lattice dimensions at –80 °C: a = 1280.8(2), b = 1017.5(1), c = 2467.8(3) pm, β = 95.04(1)°, R = 0.049. The complex anion of 1 consists of a planar ReN3S2‐heterocycle which is connected with the second rhenium atom by a μ‐nitrido bridge as well as by a μ‐dinitridosulfato(II) ligand to form a planar Re2(N)(NSN) six‐membered heterocycle. This [Cl2Re(N3S2)(μ‐NSN)(μ‐N≡ReCl3)]– unit dimerizes via one of the N‐atoms of the (NSN)4– ligand to give a centrosymmetric Re2N2 four‐membered ring. 相似文献
We studied the reactivity of an osmium vinyl complex containing a coordinated hydroxyl group OsCl2(PPh3)2[CH=C(PPh3)CHPh(OH)] (1) toward bidentate ligand 1,4-bis(diphenylphosphino)butane (DPPB),acid ligand (CO),base (Cs2CO3) and heat.Two osmium vinyl complexes OsCl2(dppb)[CH=C(PPh3)CHPh(OH)](2) and OsCl2(CO)2(PPh3)[CH=C(PPh 3)CHPh(OH)] (3),as well as two relatively rare phosphonium-containing osmafuran complexes Os(2-OCOO)(PPh3)2[CHC(PPh3)CPhO](4) and OsCl2 (PPh3)2[CHC(PPh3)CPhO](5),were obtained in high yields from these reactions.All products were characterized by NMR spectroscopy,elemental analysis,and their structures were further confirmed by single crystal X-ray diffraction. 相似文献
Mono- and Binuclear Dinitrosyl Complexes of Molybdenum and Tungsten. Crystal Structures of (PPh3Me)2[WCl4(NO)2], (PPh3Me)2[MoCl3(NO)2]2, and (PPh3Me)2[WCl3(NO)2]2 The complexes (PPh3Me)2[MCl4(NO)2] (M = Mo, W), and (PPh3Me)2[MCl3(NO)2]2, respectively, are prepared by reactions of the polymeric compounds MCl2(NO)2 with triphenylmethylphosphonium chloride in CH2Cl2, forming green crystals. According to the IR spectra the nitrosyl groups are in cis-position in all cases. The tungsten compounds as well as (PPh3Me)2[MoCl3(NO)2]2 were characterized by structure determinations with X-ray methods. (PPh3Me)2[WCl4(NO)2]: space group C2/c, Z = 4. a = 1874, b = 1046, c = 2263 pm, β = 119.99°. Structure determination with 3492 independent reflexions, R = 0.057. The compound consists of PPh3Me⊕ ions, and anions [WCl4(NO)2]2? with the nitrosyl groups in cis-position (symmetry C2v). (PPh3Me)2[WCl3(NO)2]2: Space group C2/c, Z = 4. Structure determination with 2947 independent reflexions, R = 0.059. (PPH3Me)2[MoCl3(NO)2]2: Space group P1 , Z = 1. a = 989, b = 1134, c = 1186 pm; α = 63.25°, β = 80.69°, γ = 69.94°. Structure determination with 3326 independent reflexions, R = 0.046. The compounds consist of PPh3Me⊕ ions, and centrosymmetric anions [MCl3(NO)2]22?, in which the metal atoms are associated via MCl2M bridges of slightly different lengths. One of the NO groups is in an axial position, the other one in equatorial position (symmetry C2h). 相似文献
[PPh3Cl]⊕[ReCl4(N2S2)]?; Synthese, IR-Spektrum und Kristall Strukture The title compound is prepared by the reaction of [ReCl3(NSCl)2(POCl3)] with triphenylphosphane; it formes black crystals. The crystal structure determination was solved with X-ray methods (2861 observed independent reflexions, R = 0.038). The compound crystallizes monoclinic in the space group P21/n with four formula units per unit cell. The structure consists of [PPh3Cl]⊕ cations and [ReCl4(N2S2)]? anions, in which the rhenium atom is surrounded octahedrally by four chlorine ligands and the N atoms of a ReN2S2-five-membered ring in cis-position (symmetry C2v). The Re? N bond lengths (181 pm) and the NS bond lengths (152 pm) are in the range of double bonds; the S? S distance is very long (253 pm). The i.r. spectrum is reported. 相似文献
Thionitrosyl Complexes of Ruthenium. Crystal Structure of (PPh4)2[{RuBr4(NS)}2 (μ-N2S2)] Ruthenium trichloride reacts with trithiazyl chloride, yielding cis-RuCl4 (NS)2. With triphenylmethylphosphonium chloride this forms the complex [RuCl4(NS)2Cl]? in which a chloride ion is bonded between the sulfur atoms in a chelate manner. With tetraphenylphosphonium bromide, RuCl4(NS)2 undergoes a redox reaction that affords (PPh4)2[{RuCl4(NS)}2(μ-N2S2)] which can be transformed to the title compound by the action of trimethylsilyl bromide. The i.r. spectra are reported. The crystal structure of (PPh4)2[{RuBr4(NS)}2(μ-N2S2)] · 4 CH2X2 (X ? Cl, Br) was determined with X-ray diffraction data (1534 observed reflexions, R = 0.085). Crystal data: monoclinic, space group P21/n, Z = 2, a = 1680.7, b = 1287.0, c = 1706.1 pm and β = 99.97°. The compound consists of tetraphenylphosphonium cations, CH2Br2 and CH2Cl2 molecules (statistically) and centrosymmetric anions [{RuBr4(NS)}2(μ-N2S2)]2? in which the ruthenium atoms are linked via the nitrogen atoms of a planar N2S2 ring. In the corresponding trans-positions every Ru atom has a thionitrosyl ligand with a nearly arrangement Ru?N?S with RuN and NS bond lengths of 169 und 151 pm, respectively. Four bromine atoms complete the distorted octahedral coordination of each ruthenium atom. The bromine atoms that are coplanar with the N2S2 ring form rather short Br…?S contacts with a mean distance of 317 pm. 相似文献
AsPh4[W2Cl4(N3S2)3] · CCl4; Synthesis and Crystal Structure The title compound was obtained in form of black crystals along with other products by the reaction of H2S and AsPh4[WCl4(N3S2)] in dichloromethane and subsequent addition of CCl4. Its crystal structure was determined by X-ray diffraction (3036 observed reflexions, R = 0.051). Crystal data: triclinic, space group P¯1, Z = 2, a = 1369, b = 1398, c = 1441 pm, α = 64.8, β = 68.02 and γ = 58.1°. The compound consists of AsPh4⊕ ions, CCl4 molecules and [W2Cl4(N3S2)3]? ions. In the latter, one tungsten atom is member of one planar WN3S2 ring while the second tungsten atom belongs to two such rings forming a nearly planar S2N3WN3S2 unit. Two nitrogen atoms of this unit are linked to the other tungsten atom forming a WN2W ring. Two chloro ligands at each tungsten atom complete the coordination sphere to coordination numbers of six. 相似文献
Chlorothionitrene Complexes of Rhenium. Crystal Structure of AsPh4[ReCl4(NSCl)2] · CH2Cl2 Rhenium pentachloride reacts in POCl3 solution with (NSCl)3 forming the chlorothionitrene complexes [(Cl3PO)ReCl4(NSCl)] ( I ) and [(Cl3PO)ReCl3(NSCl)2] ( II ). I reacts with AsPh4Cl in CH2Cl2 solution under abstraction of SCl2 and POCl3, yielding AsPh4[ReNCl4], while II forms the complex AsPh4[ReCl4(NSCl)2] · CH2Cl2. The i.r. spectra of the compounds are discussed and assigned. The crystal structure of AsPh4[ReCl4(NSCl)2] · CH2Cl2 was determined and refined with X-ray diffraction data (R = 0.031 for 2785 reflexions). It crystallizes in the space group Pī with two formula units per unit cell; the lattice constants are a = 1119, b = 1144, c = 1473 pm, α = 77.6, β = 70.8 and γ = 71.2°. The two NSCl ligands have cis arrangement with nearly linear Re?N?S groups, with interatomic distances corresponding to double bonds. The Re? Cl bonds are somewhat longer than usual and show no trans-effect; this is possibly due to Cl…?H? C bridges. 相似文献
Thiocomplexes of Molybdenum. Crystal Structure of a Mixed Single Crystal (PPh3Me)2[Mo2Br6(NO)4]/(PPh3Me)2[Mo2Br6S2(NO)2] The reactions of (PPh4)2MoS4 with MoBr4 and MoBr2(NO)2 resp. lead to the binuclear complexes (PPh4)2[S2MoS2MoBr3(SMe2)] and (PPh4)[S2MoS2MoBr2(NO)2], in which the molybdenum atoms are linked by sulfido bridges. The preparation of (PPh3Me)2S6 and (AsPh4)2S7 from Na2S4 and PPh3MeBr, and AsPh4Cl, respectively, in ethanol solution is described. Disulfido briges are a feature of (AsPh4)2[Mo2Br6(S2)2(SMe2)2], which is obtained from MoBr4(SMe2)2 and (AsPh4)2S7. Mixed single crystals containing 2/3 (PPh3Me)2[Mo2Br6(NO)4] and 1/3 (PPh3Me)2[Mo2Br6S2(NO)2] are formed in the reaction of MoBr2(NO)2 with (PPh3Me)2S6, as shown by X-ray single crystal structure determination. The compound crystallizes monoclinic in the space group C2/c (Internat. Tab. Nr. 15) with four formula units per unit cell (2351 independent observed reflexions, Rw = 0.037). The cell parameters are a = 1603 pm, b = 1549 pm, c = 1863 pm; β = 92.2°. The complexes consist of PPh3Me⊕ cations and the dimeric anions [Mo2Br6(NO)4]2? and [Mo2Br6S2(NO)2]2? which occur in the ratio 2:1. In these the molybdenum atoms are connected via MoBr2Mo bridges of slightly different lengths (Mo? Br 265 pm and 267 pm) forming a controsymmetric double octahedron. All molybdenum atoms have two terminal bromo ligands with Mo? Br bond lengths of 258 pm and 260 pm; in the [Mo2Br6(NO)4]2? ion each molybdenum has two covalently bonded nitrosyl groups on cis-position with Mo? N bond lengths of 183 pm. In the [Mo2Br6S2(NO)2]2? ion one of the two nitrosyl groups at each metal atom is substituted by a terminal sulfido ligand with a Mo? S bond length of 240 pm. The i.r. spectra are reported. 相似文献
(PPh4)2[(SN)ReCl3(μ‐N)(μ‐NSN)ReCl3(THF)] – a Nitrido‐Thionitrosyl‐Dinitridosulfato‐Complex of Rhenium The title compound has been prepared from PPh4[ReVIICl4(NSCl)2] with excess N(SiMe3)3 in dichloromethane solution to give red‐brown single crystals after recrystallisation from acetonitrile/THF solutions. As a by‐product PPh4[ReNCl4] is formed. (PPh4)2[(SN)ReCl3(μ‐N)(μ‐NSN)ReCl3(THF)] ( 1 ): Space group P21/n, Z = 4, lattice dimensions at –80 °C: a = 1024.1(1), b = 2350.2(1), c = 2315.4(2) pm, β = 94.09(1)°, R1 = 0.0403. In the complex anion of 1 the rhenium atoms are connected by an asymmetric Re≡N–Re bridge as well as by a (NSN)4–‐bridge to form a planar Re2N(NSN) six‐membered heterocycle. Both rhenium atoms are coordinated by three chlorine atoms, one of them by a thionitrosyl ligand, the other one by the oxygen atom of a thf molecule. 相似文献
