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 31 毫秒
1.
Tetraethyl­ammonium 7‐di­methyl­sulfanyl‐nido‐dodeca­hydro­undecaborate, [Et4N][7‐Me2S‐nido‐B11H12] or C8H20N+·C2H18B11S, is a product of the deprotonation of [7‐Me2S‐nido‐B11H13] with KHBEt3 and precipitation with tetraethyl­ammonium chloride. The effect of removing one endo‐terminal H atom is to cause a general contraction of the open‐face B—B distances.  相似文献   

2.
New Oxonium Bromochalcogenates(IV) — Synthesis, Structure, and Properties of [H3O][TeBr5] · 3 C4H8O2 and [H3O]2[SeBr6] Dark red crystals of the composition [H3O][TeBr5] · 3 C4H8O2 ( 1 ) were isolated from a saturated solution of TeBr4 in 1,4-dioxane containing a small amount of water. In this compound (space group P21/m, a = 8.922(4) Å, b = 13.204(7) Å, c = 9.853(5) Å, β = 91.82(4)° at 150 K) a square pyramidal [TeBr5]? anion has been isolated for the first time. The coordination sphere of the anion is completed to a distorted octahedron by weak interaction with a dioxane molecule of the cationic system. The [H3O]+ cations are connected to chains by dioxane molecules. At room temperature the compound is stable only in its mother liquor. Crystalline [H3O]2[SeBr6] ( 2 ) (space group Fm3m, a = 10.421(1) Å at 170 K) is a bromoselenous acid of high symmetry. The [H3O]+ ion is only weakly coordinated by Br atoms of the anion. The anions are isolated octahedral [SeBr6]2? units. The structure is isotypic to the K2[PtCl6] structure. Despite being a halogenochalcogen(IV) acid, 2 exhibits a remarkable thermal stability. Both oxonium compounds were characterized by single-crystal X-ray structure analyses. Vibrational spectra of 2 are reported.  相似文献   

3.
Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H2(C6N7)O3] · 4 H2O Sodium dihydrogencyamelurate‐tetrahydrate Na[H2(C6N7)O3]·4 H2O was obtained by neutralisation of an aqueous solution, previously prepared by hydrolysis of the polymer melon with sodium hydroxide. The crystal structure was solved by single‐crystal X‐ray diffraction ( a = 6.6345(13), b = 8.7107(17), c = 11.632(2) Å, α = 68.96(3), β = 87.57(3), γ = 68.24(3)°, V = 579.5(2) Å3, Z = 2, R1 = 0.0535, 2095 observed reflections, 230 parameters). Both hydrogen atoms of the dihydrogencyamelurate anion are directly bound to nitrogen atoms of the cyameluric nucleus, thus proving the preference of the keto‐tautomere in salts of cyameluric acid in the solid‐state. The compound forms a layer‐like structure with an extensive hydrogen bonding network.  相似文献   

4.
(C2H10N2)[BPO4F2] — Strukturbeziehungen zwischen [BPO4F2]2— und [Si2O6]4— Colourless crystals of (C2H10N2)[BPO4F2] were prepared from mixture of ethylendiamine, H3BO3, BF3 · C2H5NH2, H3PO4 and HCl under mild hydrothermal conditions (220 °C). The crystal structure was determined by single crystal methods (triclinic, P1¯ (no. 2), a = 451.85(5) pm, b = 710.20(8) pm, c = 1210.2(2) pm, α = 86.08(1)°, β = 88.52(2)°, γ = 71.74(1)°, Z = 2) and contains infinite tetrahedral zweier‐single‐chains {[BPO4F2]2—} which are isoelectronic (48e) with the polyanions {[Si2O6]4—} of the pyroxene family.  相似文献   

5.
Diammonium tricyanomelaminate dihydrate [NH4]2[C6N9H] · 2 H2O ( 1 ) and dimelaminium tricyanomelaminate melamine dihydrate [C3N6H7]2[C6N9H] · C3N6H6 · 2 H2O ( 2 ) were obtained by metathesis reactions from Na3[C6N9] in aqueous solution and characterized by single‐crystal X‐ray diffraction and 15N solid‐state NMR spectroscopy ( 1 ). Both salts contain mono‐protonated tricyanomelaminate (TCM) anions and crystallize as dihydrates. Considering charge balance requirements, the crystal structure of 1 (C2/c, a = 3181.8(6) pm, b = 360.01(7) pm, c = 2190.4(4) pm, β = 112.39(3)°, V = 2319.9(8) 106 · pm3) can best be described by assuming a random distribution of an ammonium ion – crystal water pair over two energetically similar sites. Apart from two melaminium cations, 2 (P21/c, a = 674.7(5) pm, b = 1123.6(5) pm, c = 3400.2(5) pm, β = 95.398(5), V = 2566(2) 106 · pm3) contains one neutral melamine per formula unit acting as an additional “solvent” molecule and yielding a donor‐acceptor type of π–stacking interaction.  相似文献   

6.
Novel Oxonium Halogenochalcogenates Stabilized by Crown Ethers: [H3O(Dibromo‐benzo‐18‐crown‐6)]2[Se3Br10] and [H5O2(Bis‐dibromo‐dibenzo‐24‐crown‐8]2[Se3Br8] Two novel complex oxonium bromoselenates(II,IV) and –(II) are reported containing [H3O]+ and [H5O2]+ cations coordinated by crown ether ligands. [H3O(dibromo‐benzo‐18‐crown‐6)]2[Se3Br10] ( 1 ) and [H5O2(bis‐dibromo‐dibenzo‐24‐crown‐8]2[Se3Br8] ( 2 ) were prepared as dark red crystals from dichloromethane or acetonitrile solutions of selenium tetrabromide, the corresponding unsubstituted crown ethers, and aqueous hydrogen bromide. The products were characterized by their crystal structures and by vibrational spectra. 1 is triclinic, space group (Nr. 2) with a = 8.609(2) Å, b = 13.391(3) Å, c = 13.928(3) Å, α = 64.60(2)°, β = 76.18(2)°, γ = 87.78(2)°, V = 1404.7(5) Å3, Z = 1. 2 is also triclinic, space group with a = 10.499(2) Å, b = 13.033(3) Å, c = 14.756(3) Å, α = 113.77(3)°, β = 98.17(3)°, γ = 93.55(3)°. V = 1813.2(7) Å3, Z = 1. In the reaction mixture complex redox reactions take place, resulting in (partial) reduction of selenium and bromination of the crown ether molecules. In 1 the centrosymmetric trinuclear [Se3Br10]2? consists of a central SeIVBr6 octahedron sharing trans edges with two square planar SeIIBr4 groups. The novel [Se3Br8]2? in 2 is composed of three planar trans‐edge sharing SeIIBr4 squares in a linear arrangement. The internal structure of the oxonium‐crown ether complexes is largely determined by the steric restrictions imposed by the aromatic rings in the crown ether molecules, as compared to complexes with more flexible unsubstituted crown ether ligands.  相似文献   

7.
Molybdenum(II) Halide Clusters with two Alcoholate Ligands: Syntheses and Crystal Structures of (C18H36N2O6Na)2[Mo6Cl12(OCH3)2] and (C18H36N2O6Na)2[Mo6Cl12(OC15H11)2] · 2C4H6O3 . Reaction of Mo6Cl12 with two equivalents of sodium methoxide in the presence of 2,2,2-crypt yields (C18H36N2O6Na)2[Mo6Cl12(OCH3)2] ( 1 ), which can be converted to (C18H36N2O6Na)2[Mo6Cl12(OC15H11)2] · 2C4H6O3 ( 2 ) by metathesis with 9-Anthracenemethanole in propylene carbonate. As confirmed by X-ray single crystal structure determination ( 1 : C2/m, a=25.513(8) Å, b=13.001(3) Å, c=10.128(3) Å, β=100.204(12)°; : C2/c, a=15.580(5) Å, b=22.337(5) Å, c=27.143(8) Å, β=98.756(10)°) the compounds contain anionic cluster units [Mo6ClCl(ORa)2]2? with two alcoholate ligands in terminal trans positions ( 1 : d(Mo—Mo) 2.597(2) Å to 2.610(2) Å, d(Mo—Cli) 2.471(3) Å to 2.493(4) Å, d(Mo—Cla) 2.417(8) Å and 2.427(8) Å, d(Mo—O) 2.006(13) Å; 2 : d(Mo—Mo) 2.599(3) Å to 2.628(3), d(Mo—Cli) 2.468(8) Å to 2.506(7) Å, d(Mo—Cla) 2.444(8) Å and 2.445(7) Å, d(Mo—O) 2.012(19) Å).  相似文献   

8.
In the centrosymmetric title complex, [Ni(C7H7N4O3)2(C5H5N)2], the coordination geometry about the Ni2+ ion is octahedral, with two deprotonated 1‐methyl‐3‐(p‐nitro­phenyl)­triazenide 1‐oxide ions, viz. [O2N­C6H4­NNN(O)­CH3]?, acting as bidentate ligands (four‐electron donors). Two neutral pyridine (py) mol­ecules complete the coordination sphere in positions trans to each other. The triazenide 1‐oxide ligand is almost planar, the largest interplanar angle of 8.80 (12)° being between the phenyl ring of the p‐nitro­phenyl group and the plane defined by the N3O moiety. The Ni—Ntriazenide, Ni—O and Ni—Npy distances are 2.0794 (16), 2.0427 (13) and 2.1652 (18) Å, respectively.  相似文献   

9.
Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH and (C18H36N2O6Na)2[Mo6Cl8(OC6H5)6] . The reaction of Na2[Mo6Cl8(OCH3)6] and 2,2,2-crypt yields (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6 CH3OH ( 1 ), which is converted to (C18H36N2O6Na)2[Mo6Cl8(OC6H5)6] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo6Cl8i(ORa)6]2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo6Cl8(OC6H5)6]2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.  相似文献   

10.
Synthesis and Crystal Structure of the First Oxonitridoborate — Sr3[B3O3N3] The cyclotri(oxonitridoborate) Sr3[B3O3N3] was synthesized at 1450 °C as coarsely crystalline colourless crystals by the reaction of SrCO3 with poly(boron amide imide) using a radiofrequency furnace. The structure was solved by single‐crystal X‐ray diffractometry (Sr3[B3O3N3], Z = 4, P21/n, a = 663.16(2), b = 786.06(2), c = 1175.90(3) pm, η = 92.393(1)°, R1= 0.0441, wR2 = 0.1075, 1081 independent reflections, 110 refined parameters). Besides Sr2+ there are hitherto unknown cyclic [B3O3N3]6— ions (B—N 143.7(10) — 149.1(9) pm, B—O 140.5(8) — 141.4(8) pm).  相似文献   

11.
The two novel thioantimonate(V) compounds [Mn(C6H18N4)(C6H19N4)]SbS4 ( I ) and [Mn(C6H14N2)3][Mn(C6H14N2)2(SbS4)2]·6H2O ( II ) were synthesized under solvothermal conditions by reacting elemental Mn, Sb and S in the stoichiometric ratio in 5 ml tris(2‐aminoethyl)amine (tren) at 140 °C or chxn (trans‐1, 2‐diaminocyclohexane, aqueous solution 50 %) at 130 °C. Compound I crystallises in the triclinic space group P1¯, a = 9.578(2), b = 11.541(2), c = 12.297(2)Å, α = 62.55(1), β = 85.75(1), γ = 89.44(1)°, V = 1202.6(4)Å3, Z = 2, and II in the monoclinic space group C2/c, a = 32.611(2), b = 13.680(1), c = 19.997(1)Å, β = 117.237(5)°, V = 7931.7(8)Å3, Z = 4. In I the Mn2+ cation is surrounded by one tetradentate tren molecule, one protonated tren acting as a monodentate ligand and a monodentate [SbS4]3— anion yielding a distorted octahedral environment. In II one unique Mn2+ ion is in an octahedral environment of three bidentate chxn molecules and the second independent Mn2+ ion is coordinated by two chxn ligands and two monodentate [SbS4]3— units leading to a distorted octahedral surrounding. The compounds were investigated and characterized with thermal and spectroscopic methods.  相似文献   

12.
Dicarboxylate Groups as Ligands and Anions in Aquamagnesium Complexes: Crystal Structures of [Mg (C4H2O4)(H2O)4] · H2O and [Mg(H2O)6](C4HO4)2 · 2H2O ((C4H2O4)2— = Fumarate; (C4HO4) = Hydrogenacetylenedicarboxylate) Crystals of tetraaqua(fumarato)magnesium‐hydrate ( 1 ) and hexaaquamagnesium‐bis(hydrogenacetylenedicarboxylate)‐dihydrate ( 2 ) were prepared by reacting MgCl2 with sodium fumarate and acetylenedicarboxylic acid, respectively. In 1 cis‐Mg(H2O)4 units are bridged by α, Ö‐bonded fumarate groups. The resulting zig zag chains exhibit the maximum symmetry compatible with space group symmetry C2/c. 2 consists of layers of voluminous [Mg(H2O)6]2+ cations alternating with layers of C4HO4 anions. The nearly planar anions are held together by parallel stacking and by short hydrogen bonds. Both structures contain efficient H bridging systems. 1 : Space group C2/c, Z = 4, lattice constants at 20 °C: a = 5.298(1), b = 13.178(2), c = 13.374(2)Å; ß = 94.79(2)°, R1 = 0.024. 2 : Space group P1, Z = 1, lattice constants at 20 °C: a = 5.985(1), b = 6.515(1), c = 11.129(1)Å; α = 105.24(2), ß = 91.87(3), γ = 90.92(1)°, R1 = 0.034.  相似文献   

13.
The reaction of the organolithium derivative {2, 6‐[P(O)(OEt)2]2‐4‐tert‐Bu‐C6H2}Li ( 1 ‐Li) with [Ph3C]+[PF6] gave the substituted biphenyl derivative 4‐[(C6H5)2CH]‐4′‐[tert‐Bu]‐2′, 6′‐[P(O)(OEt)2]2‐1, 1′‐biphenyl ( 5 ) which was characterized by 1H, 13C and 31P NMR spectroscopy and single crystal X‐ray analysis. Ab initio MO‐calculations reveal the intramolecular O···C distances in 5 of 2.952(4) and 2.988(5)Å being shorter than the sum of the van der Waals radii of oxygen and carbon to be the result of crystal packing effects. Also reported are the synthesis and structure of the bromine‐substituted derivative {2, 6‐[P(O)(OEt)2]2‐4‐tert‐Bu]C6H2}Br ( 9 ) and the structure of the protonated ligand 5‐tert‐Bu‐1, 3‐[P(O)(OEt)2]2C6H3 ( 1 ‐H). The structures of 1 ‐H, 5 , and 9 are compared with those of related metal‐substituted derivatives.  相似文献   

14.
Preparation, Characterisation, and Crystal Structures of the Pseudohalogen Crown Ether Complexes [K([18]crown‐6)(X)(OPPh3)] (X = N3, OCN and SCN) The potassium crown ether complexes [K([18]Crown‐6)(X)(OPPh3)] (with X = N3, OCN and SCN) can be obtained by reaction of KX with 18‐crown‐6 (1, 4, 7, 10, 13, 16‐hexaoxacyclooctadecane and triphenylphosphane in THF exposed to UV light. All crown ether complexes were characterized by means of vibrational spectroscopy and X‐ray diffraction. They crystallize in the rhombic pointgroup R3m with three molecules in the unit cell: [K([18]crown‐6) (N3)(OPPh3)] ( 1 ): lattice constants at 293 K: a = b = 14.213(2) Å; c = 13.951(2) Å; R1 = 0.0249. [K([18]crown‐6)(OCN)(OPPh3)] ( 2 ): a = b = 14.239(2) Å; c = 13.8927(14) Å; R1 = 0.0257. [K([18]crown‐6)(NCS)(OPPh3)] ( 3 ): a = b = 14.339(2) Å; c = 14.266(2) Å; R1 = 0.0264.  相似文献   

15.
The mixed‐amide phosphinates, rac‐phenyl (N‐methylcyclohexylamido)(p‐tolylamido)phosphinate, C20H27N2O2P, (I), and rac‐phenyl (allylamido)(p‐tolylamido)phosphinate, C16H19N2O2P, (II), were synthesized from the racemic phosphorus–chlorine compound (R,S)‐(Cl)P(O)(OC6H5)(NHC6H4p‐CH3). Furthermore, the phosphorus–chlorine compound ClP(O)(OC6H5)(NH‐cyclo‐C6H11) was synthesized for the first time and used for the synthesis of rac‐phenyl (benzylamido)(cyclohexylamido)phosphinate, C19H25N2O2P, (III). The strategies for the synthesis of racemic mixed‐amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N1)P(=O)(O)(N2) environment. In (I) and (II), the p‐tolylamido substituent makes a longer P—N bond than those involving the N‐methylcyclohexylamido and allylamido substituents. In (III), the differences between the P—N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with the N—H unit in hydrogen‐bonding interactions, viz. an N—H...O=P hydrogen bond for (I) and (N—H)(N—H)...O=P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).  相似文献   

16.
The title complexes, catena‐poly[[aqua(1,10‐phenanthroline‐κ2N,N′)­cobalt(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ2O1:O4], [Co(C8H4O4)(C12H8N2)(H2O)], (I), and catena‐poly[[[(di‐2‐pyridyl‐κN‐amine)copper(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ4O1,O1′:O4,O4′] hydrate], [Cu(C8H4O4)(C10H9N3)]·H2O, (II), take the form of zigzag chains, with the 1,4‐benzene­di­carboxyl­ate ion acting as an amphimonodentate ligand in (I) and a bis‐bidentate ligand in (II). The CoII ion in (I) is five‐coordinate and has a distorted trigonal–bipyramidal geometry. The CuII ion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the trans O—Cu—O bonds and with a trans O—Cu—O angle of only 137.22 (8)°.  相似文献   

17.
Two new oxovanadium(V) complexes, [2‐MePyH][VvO2(L)] (3) and[2‐EtPyH][VvO2,(L)] (4) (salicylaldehyde 5‐bromo salicyloylhydrazone is abbreviated as H2L; 2‐MePyH is protonated 2‐Mepyridine; 2‐EtPyH presents protonated 2‐Et‐pyridine) were obtained from a reaction of VOSO4 and H2L in acetonitrile‐methanol with small quantity of 2‐Me‐pyridine or 2‐Et‐pyridine, and characterized by X‐ray diffraction and spectroscopic methods. Crystal data: [2‐MePyH][VO2(L)] (3), C20H17N3O5BrV, Mr = 510.2, monoclinic, P21/n, a = 0.7363(1) nm, 6 = 0.9514(1) nm, c = 2.8594(2) nm, β = 95.305(2)°, Z = 4 and V=1.9946(3) nm3, μ(Mo Kα) = 2.539 mm?1; [2‐EtPyH][VO2(L)] (4), C21H19N3 O3BrV, Mr = 524.2, triclinic, P1 , a = 0.8051(1) nm, b = 0.9413(1) nm, c = 1.4648(2) nm, α=99.1900(10)°, α = 99.4530(10)°, γ = 104.6670(10)°, Z = 2 and V= 1.0355(2) nm3, μ(Mo Kα) = 2.448 mm?1, X‐Ray analyses revealed that the crystal structures of 3 and 4 have similar packing modes.  相似文献   

18.
Coordination Polymeric 1, 2‐Dithiooxalato and 1, 2‐Dithiosquarato Complexes. Syntheses and Structures of [BaCr2(bipy)2(1, 2‐dtox)4(H2O)2], [Ni(cyclam)(1, 2‐dtsq)]·2DMF, [Ni(cyclam)Mn(1, 2‐dtsq)2(H2O)2]·2H22, and [H3O][H5O2][Cu(cyclam)]3[Cu2(1, 2‐dtsq)3]2 1, 2‐Dithioxalate and 1, 2‐dithiosquarate ions have a pair of soft and hard donor centers and thus are suited for the formation of coordination polymeric complexes containing soft and hard metal ions. The structures of four compounds with building blocks containing these ligands are reported: In [BaCr2(bipy)2(1, 2‐dtox)4(H2O)2] Barium ions and pairs of Cr(bipy)(1, 2‐dtox)2 complexes form linear chains by the bisbidentate coordination of the dithiooxalate ligands towards Ba2+ and Cr3+. In [Ni(cyclam)(1, 2‐dtsq)]·2DMF short NÖH···O hydrogen bonds link the NiS2N4‐octahedra with C2v‐symmetry to an infinite chain. In [Ni(cyclam)Mn(1, 2‐dtsq)2(H2O)2]·2H2O the 1, 2‐dithiosquarato ligand shows a rare example of S‐coordination towards manganese(II). The sulfur atoms of cis‐MnO2S4‐polyedra are weakly coordinated towards the axial sites of square‐planar NiN4‐centers, thus forming a zig‐zag‐chain of Mn···Ni···Mn···Ni polyhedra. [H3O][H5O2][Cu (cyclam)]3[Cu2(1, 2‐dtsq)3]2 contains square planar [CuII(cyclam)]2+ ions and dinuclear [CuI2(1, 2‐dtsq)3]4— ions. Here each copper atom is trigonally planar coordinated by S‐donor atoms of the ligands. The Cu…Cu distance is 2.861(4)Å.  相似文献   

19.
The reaction of propane‐1,3‐diamine hydrochloride, 18‐crown‐6 and zinc(II) chloride in methanol solution yields the title complex salt [systematic name: propane‐1,3‐diaminium tetrachloridozincate(II)–1,4,7,10,13,16‐hexaoxacyclooctadecane (1/1)], (C3H12N2)[ZnCl4]·C12H24O6, with an unusual supramolecular structure. The diprotonated propane‐1,3‐diaminium cation forms an unexpected 1:1 supramolecular rotator–stator complex with the crown ether, viz. [C3H12N2(18‐crown‐6)]2+, in which one of the –NH3+ substituents nests in the crown and interacts through N—H...O hydrogen bonding. The other –NH3+ group interacts with the [ZnCl4]2− anion via N—H...Cl hydrogen bonding, forming cation–crown–anion ribbons parallel to [010].  相似文献   

20.
3‐(4‐carboxyphenyl)‐1‐methyltriazene N‐oxide reacts with KOH in methanol/pyridine to give {K[O2C‐C6H4‐N(H)NN(CH3)O]·4H2O}n, Potassium‐3‐(4‐carboxylatophenyl)‐1‐methyltriazene N‐oxide). The terminal carboxylato group of the anion does not interact with the cation. In the crystal lattice of {K(C8H8N3O3)·4H2O}n each three of the four water molecules interact with two potassium cations, every K+ ion being the centre of six bridging K···O interactions. Potassium cations interact further with the terminal N‐oxigen atom of single [C8H8N3O3]? anions achieving two parallel {C8H8N3O3?K+}n chains, which are linked through water molecules. The resulting polymeric, one‐dimensional chain, is operated by a screw axis 21 parallel to the crystallographic direction [010], along and equidistant to the K+ centres. The coordination of the K+ centres involves a distortion of the boat conformation of elementary sulfur (S8) with the ideal C2v symmetry.  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