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1.
A coordination polymer {[Cu(C11H20N4O2)2(H2O)]2+·2(NO 3 ? )} n (I) is synthesized and analyzed using single-crystal XRD. The crystals are monoclinic: space group P2/c, a = 12.5237(6) Å, b = 7.3310(3) Å, c = 16.8926(8) Å, β = 92.569(4)°, V = 1549.38(13) Å3, ρcalc = 1.47 g/cm3, and Z = 2. The copper atom is in a special position in the second-order axis. The coordination polyhedron of the metal is a trigonal bipyramid. In the axial direction, it is coordinated by two oxygen atoms O(1) of the organic ligand molecules connected by the symmetry operation [?x, y, 0.5-z]; the angle O(1)Cu(1)O(1) i is 175.16(15)°. In the equatorial direction, the copper atom is coordinated by oxygen atoms O(2) of two ligand molecules connected with the reference molecule by the symmetry operations [?x, y, 0.5-z] and [x, 1-y, ?0.5+z] and the water molecule O(6) in a special position on the twofold axis. The OCuO angles between the equatorial oxygen atoms are 96.80(16)–131.60(8)°, and those between the axial and equatorial atoms are 87.58(8)-91.60(10)°. It is noteworthy that the length of the Cu-O(1) bond (1.955(2) Å) with the axial carbonyl oxygen atom is somewhat shorter than the bond (2.060(3) Å) with the equatorial atom. Nitrate anions are outside the coordination sphere of the metal. The Cu…Cu distance in the polymer is 8.33 Å. To confirm the purity of the sample of I, the powder X-ray pattern is refined by the Rietveld method; the lattice parameters at room temperature are: a = 12.535(4) Å, b = 7.3161(13) Å, c = 16.841(5) Å, β = 92.11(2)°, and V = 1543.4(7) Å3.  相似文献   

2.
{[Sc2(C11H20N4O2)3(H2O)6]6+ · 6(NO 3 ? )} n (I), a coordination metallopolymer, has been synthesized for the first time and analyzed by X-ray diffraction. Crystals are tetragonal, space group P $\bar 4$ 21 c, a = 21.9797(6) Å, c = 12.7499(6)Å, V = 6159.6(4) Å3, ρcalcd = 1.392 g/cm3, Z = 4. The scandium atom is coordinated to the three oxygen atoms of spirocarbone molecules, which are related to the basal molecules by the symmetry codes 3/2 ? y, 3/2 ? x, 1/2 + z and 3/2 ? y, 3/2 ? x, ? 1/2 + z, and also to three water molecules. The coordination number of scandium is 6. The coordination polyhedron of scandium is a slightly distorted octahedron with OScO angles within 84.70(15)°–95.86(14)° and 172.77(16)°–173.84(15)°. Nitrate anions are in the outer coordination sphere of the metal. The purity of compound I is verified via the Rietveld refinement of its X-ray powder diffraction pattern; the unit cell parameters at room temperature are a = 22.0589(6) Å, c = 12.7806(6) Å, V = 6219.0(6) Å3. Lines unrelated to the major phas are not observed in the X-ray diffraction pattern. The content of the major phase is 100 ± 1%.  相似文献   

3.
The coordination polymer of cobalt(II) nitrate with bicyclic bis(urea), 4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane-2,8-dione (Sk) {[Co(C11H20N4O2)2(H2O), Co(C11H20N4O2)2(H2O)2]4+(NO 3 - )4} n (I), is synthesized for the first time, and its atomic structure is determined (CIF file CCDC no. 925792). The crystals of compound I are monoclinic: space group P2/c, a = 26.1284(6), b = 7.1763(2), c = 17.1825(5) Å, β = 105.042(3)°, V = 3111.43(15) Å3, ρcalcd = 1.474 g/cm3, Z = 2. The powder X-ray pattern at 293 K is refined using the Rietveld method to confirm the single-phase character of the obtained sample of powdered compound I: a = 26.1456(9), b = 7.1810(4), c = 17.1997(11) Å, β = 105.016(3)°, V = 3119.0(3) Å3. The content of the major phase of compound I in the sample is 100 ± 1%, and impurity phases are absent. The crystal of compound I contains two types of chains oriented along the crystallographic direction [001] with similar structures but differed in the coordination numbers of the cobalt atoms. The Co(1) atom has a coordination number of 5 (trigonal bipyramid), and the coordination number of the Co(2) atom is 6 (octahedron). The nitrate anions are uncoordinated.  相似文献   

4.
A coordination polymer {[Mn(H2O)2(C11H20N4O2)2]2+·2(NO 3 ? )} n is synthesized and its structure is determined. The crystals are monoclinic: space group P21/c, a = 12.3771(3) Å, b = 14.8775(3) Å, c = 18.1388(4) Å, β = 106.611(2)°, V = 3200.70(12) Å3, d x = 1.44 g/cm3, Z = 4. Manganese ions are coordinated with four oxygen atoms of four organic ligands (two unique) and two water molecules. The coordination polyhedron is a distorted octahedron; the O-Mn-O angles between the adjacent oxygen atoms fall within 83.96(5)–98.11(5)°. The nitrate anions are in the outer coordination sphere. The Mn...Mn distances in the polymer are 8.56 Å. In the crystal, polymeric coordination chains are joined in layers perpendicular to the b axis by hydrogen bonds involving the organic ligands, water molecules, and nitrate anions.  相似文献   

5.
The coordination polymer {[UO2(NO3)2(C11H20N4O2)] · 2H2O} n (I) was obtained and examined by X-ray diffraction. The crystals are monoclinic, space group C2/c; a = 23.1386(13), b = 5.41575(15), c = 19.7769(11) Å, β = 125.285(8)°, V = 2023.01(17) Å3, ρcalcd = 2.20 g/cm3, Z = 4. The U atom occupies a special position in the center of inversion. Its coordination polyhedron is a distorted hexagonal bipyramid with axial oxo ligands. In the equatorial plane, the U(1) atom is coordinated by four O atoms of two bidentate nitrate anions and two O atoms of two carbonyl groups of organic spirocarbone (Sk) molecules, which are related by the symmetry operation (0.5 ? x, 0.5 ? y, ?z). In the crystal, polymer chains are parallel to the direction (101). Water molecules are hydrogen-bonded to the N(1) atom of ligand Sk; in addition, they are linked together by the intermolecular hydrogen bonds O(6)-H(6d)…O(6)i(i1/2 ? x, ?1/2 + y, 1/2 ? z); H…O 2.11 Å angle O-H…O 160°) and to the nitrate anions by the hydrogen bonds O(6)-H(6e)…O(3)i; H…O 2.29 Å; the angle O-H…O 149°). In the crystal, hydrogen-bonded water molecules form chains along the axis y that are perpendicular to the coordination polymers. To verify the purity of complex I, the Rietveld refinement of its X-ray powder diffraction pattern was performed. At room temperature, the unit cell parameters are a = 23.2965(6), b = 5.51225(15), c = 19.8588(6) Å, β = 125.6063(17)°, V = 2073.40(10) Å3.  相似文献   

6.
Binuclear complexes of Sm(III), Eu(III), Gd(III), Tb(III), and Dy(III) nitrates with 4,4,10,10-tetramethyl-1,3,7,9-tetraazospiro[5.5]undecane-2,8-dione (C11H20N4O2, SC)—[Sm(NO3)3(SC)(H2O)]2(I), [Eu(NO3)3(SC)(H2O)]2 (II), [Gd(NO3)2(SC)(H2O)3)]2(NO3)2 (III), [Tb(NO3)3(SC)(H2O)]2 (IV), [Dy(NO3)3(SC)(H2O)]2 (V), are synthesized, and their X-ray diffraction analyses are carried out. The crystals of complexes I–V are monoclinic: space group P21/n for III and P21/c for I, II, IV, and V. In centrosymmetric coordination complexes II, III, IV, and V, the Ln atoms are coordinated by two O(1) and O(2) atoms of two molecules of the SC ligands bound by a symmetry procedure (1 ? x, ?y, 1 ? z), three bidentate nitrate anions, and a water molecule. The coordination numbers of the metal atoms are equal to 9, and the coordination polyhedra are considerably distorted three-capped trigonal prisms, whose bases include the O(1), O(2), O(12) and O(3), O(7), O(9) atoms. The dihedral angle between the bases of the prism is 18°, and that between the mean planes of the side faces is 55°–71° for I, 17° and 55°–71° for II, 16° and 55°–70° for IV, and 16° and 55°–70° for V. The Sm...Sm distance in complex I is 9.44 Å, Eu...Eu in II is 9.42 Å, Tb...Tb in IV is 9.36Å, and Dy...Dy in V is 9.36Å. The gadolinium atom in complex III is coordinated by two oxygen atoms of two ligand molecules bound by a symmetry procedure (?x, ?y + 1, ?z + 1), two bidentate nitrate anions, and three water molecules. One of the nitro groups in compound III is localized in the external coordination sphere of the metal. The coordination number of gadolinium is 9, and the coordination polyhedron is a significantly distorted three-capped trigonal prism, whose base includes the O(1), O(2), O(7) and O(4), O(5), O(9) atoms. The dihedral angle between the bases of the prism is 22.8°, and that between the mean planes of the side faces is 53°–72°. The Gd...Gd distance in complex III is 9.17 Å.  相似文献   

7.
Two novel spiro compounds,3-benzylidene-1,5-dioxaspiro[5.5]undecane-2,4-dione 1 and 3-(2-fluorobenzylidene)-1,5-dioxaspiro[5.5]undecane-2,4-dione 2,have been synthesized and characterized by X-ray single-crystal diffraction,IR and elemental analysis.Compound 1 belongs to the monoclinic system,space group P21/n with a=12.326(3),b=5.6420(11),c=20.089(4),β= 101.79(3)o,C16H16O4,Mr= 272.29,V=1367.7(5)3,Z=4,Dc=1.322g/cm3,F(000)=576,μ(MoKa)=0.095 mm-1,the final R=0.0420 and wR=0.1159.Compound 2 is of monoclinic system,space group P21/n with a=12.283(3),b=5.6367(11),c=20.055(4),β=102.00(3)o,C16H15FO4,Mr=290.28,V=1358.2(5)3,Z=4,Dc=1.420 g/cm3,F(000)=608,μ(MoKa)=0.110 mm-1,the final R=0.0353 and wR=0.0860.  相似文献   

8.
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10.
The synthesis and liquid-crystalline properties of 1,5-dioxa- and 1,5-dithiaspiro[5.5]undecane, 7,16-dioxa-dispiro[5.2.5.2]hexadecane and 1,5,10,14-tetraoxa-dispiro[5.2.5.2]hexadecane derivatives are described. The effects of terminal sub-stituents and molecular structure on the liquid-crystalline properties of these materials are discussed.  相似文献   

11.
Abstract

The synthesis and liquid-crystalline properties of 1,5-dioxa- and 1,5-dithiaspiro[5.5]undecane, 7,16-dioxa-dispiro[5.2.5.2]hexadecane and 1,5,10,14-tetraoxa-dispiro[5.2.5.2]hexadecane derivatives are described. The effects of terminal sub-stituents and molecular structure on the liquid-crystalline properties of these materials are discussed.  相似文献   

12.
A facile two-directional synthesis of new pyrimido[5,4-d]pyrimidine-2,8-dione was reported via an efficient reaction of premade bis-aldehydes and 1-(2-amino-1,2-dicyanovinyl)-3-phenylurea in the presence of triethylamine as the base and Cu (II) as catalyst. As there is controversy about the formation of two types of products, that is, purine or pyrimidine ring containing compounds in the reaction of diaminomaleonitrile with isocyanates and aldehydes, the computational model chemistry has been employed to obtain new insight about this reaction and determining the dominant pathway of the process. Using DFT model, two alternative pathways have been explored and geometrical isomerization of central double bond has been considered. Accordingly, the evaluated energy barriers affirm the formation of six-membered pyrimidine ring as the major product in the presence of CuCl2 as the catalyst and MeOH as solvent.  相似文献   

13.
14.
NMR spectroscopy, X-ray diffraction analysis, and quantum chemical calculations were used for conformational behavior study of partially alkylated thiacalix[4]arenes bearing methyl (1), ethyl (2), or propyl (3) groups at the lower rim. The conformational properties are governed by two basic effects: (i) stabilization by intramolecular hydrogen bonds, and (ii) sterical requirements of the alkoxy groups at the lower rim. While the monosubstituted derivatives 1a and 3a adopt the cone conformation in solution, distally disubstituted compounds 1b, 1'b, 2b, 2'b, 3b, and 3'b exhibit several interesting conformational features. They prefer pinched cone conformation in solution, and, except for 3'b, they form also 1,2-alternate conformation, which is flexible and undergoes rather fast transition between two identical structures. The crystal structures of the compounds 1b, 2b, 2'b, and 3b revealed yet quite rare 1,2-alternate conformation forming molecular channels held together by pi-pi interactions. Different channels-with hexagonal symmetry, 0.26 nm wide-are formed in the crystal structure of the pinched cone conformation of 3b. An uncommon hydrogen bonding pattern was found in dimethoxy and dipropoxy derivatives 1'b and 3'b that adopt distorted cone conformations in crystal. Trialkoxy-substituted compounds 1c and 3c adopt the partial cone conformation in solution. A higher mobility of methyl derivative 1c enables also existence of the cone conformer.  相似文献   

15.
《Tetrahedron》1986,42(2):655-661
A stable derivative of cyclooctatrienyne (1), namely 1,4,7,10-tetramethyl-5,6-didehydrodibenzo-[a,e]cyclooctene (3), has been synthesized and fully characterized. X-Ray crystallographic analyses indicate that 3 adopts a “butterfly” conformation intermediate between those of virtually planar 5,6-didehydrodibenzo-[a,e]cyclooctene (2) and tub-shaped 1,4,7,10-tetramethyldibenzo[a,e]cyclooctene(16). The methyl substituents effectively shield the otherwise rather exposed strained triple bond of 3 and kinetically stabilize it against dimerization and/or air oxidation.  相似文献   

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18.
An efficient one-pot strategy for the synthesis of a new family of imidazo[1,4]diazepines has been developed and its mechanism has been proposed, which follows a seven-membered ring closure reaction. The condensation of 2- and 4-imidazolecarboxaldehyde with pyrazole amines provides six compounds 1–6, which are based on two types of fused tricyclic scaffolds. All presented compounds were fully spectroscopically characterized and their structure was unambiguously determined by single crystal X-ray crystallography. Molecular docking studies reveal a high similarity between binding modes of diazepines 1, 6 and eticlopride in the dopamine D3 receptor, as well as between enantiomers 2S, 6S and nortriptyline in dopamine transporter DAT.  相似文献   

19.
Abstract

Herein, we describe an improved method to synthesise mono-, di- and tetra-cyanocalix[4]arene and report their crystal structure determinations. We also report our attempts to further functionalise the cyanocalix[4]arenes into dithiadiazolyl-calix[4]arenes, and propose a hypothesis as to why the cyano group on a calix[4]arene is an extremely challenging group to modify.  相似文献   

20.
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