Isolation and structure of an 18-membered macrocycle containing two diselenide linkages and its precursor

2019 ◽  
Vol 75 (3) ◽  
pp. 336-341
Author(s):  
Saravanan Raju ◽  
Ray J. Butcher ◽  
Harkesh B. Singh
Keyword(s):  
Unit Cell ◽  
Amino Groups ◽  
Space Group ◽  
Macrocyclic Ring ◽  
Bond Lengths

The structures of the 18-membered diselenide-linked macrocycle 10,27-di-tert-butyl 11,28-dioxo-2,3,19,20-tetraselena-10,12,27,29-tetraazapentacyclo[28.4.0.04,9.013,18.021,26]tetratriaconta-1(30),4(9),5,7,13,15,17,21,23,25,31,33-dodecaene-10,27-dicarboxylate, C36H34N4O6Se4, and its precursor di-tert-butyl 2,2′-[diselane-1,2-diylbis(2,1-phenylene)]dicarbamate, C22H28N2O4Se2, are reported. The precusor to the macrocycle contains two tert-butyl phenylcarbamate arms connected to a diselenide group, with Se—C and Se—Se bond lengths of 1.914 (4) and 2.3408 (6) Å, respectively. The macrocycle resides on a crystallographic center of inversion in space group P\overline{1} with one molecule in the unit cell (Z′ = 1 \over 2). It contains an 18-membered macrocyclic ring with two diselenide linkages. In this macrocycle, there are two free and two protected amino groups.

N-TrimethylsilyMminotriphenylphosphoran-Kupfer(II)-chlorid, [Me3 SiNPPh3 · CuCl 2 ]2 Synthese und Kristallstruktur / N-Trimethylsilyl-iminotriphenylphosphorane Copper(II) Chloride, [Me3 SiNPPh3 · CuCl 2] 2 Synthesis and Crystal Structure

1988 ◽  
Vol 43 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Dieter Fenske ◽  
Eberhard Böhm ◽  
Kurt Dehnicke ◽  
Joachim Strähle
Keyword(s):  
Crystal Structure ◽  
Coordination Number ◽  
Structure Determination ◽  
Ir Spectrum ◽  
Title Compound ◽  
Unit Cell ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Bond Lengths ◽  
Moisture Sensitive

Abstract The title compound has been prepared by the reaction of N-trimethylsilyl-iminotriphenylphos-phorane with copper(II) chloride in boiling CCl4 /C2H5OH, and forms moisture sensitive crystals, which are green in transmittance and black in reflexion. [Me3SiNPPh3 · CuCl2 ] 2 was characterized by its IR spectrum as well as by a crystal structure determination (4197 observed, independent reflexions, R = 0.049). The lattice dimensions are at 20 °C: a = 1102.7. b = 1407.3. c = 1560.2 pm; β = 94.27°; space group P21/n with two formula units in the unit cell. The complex consists of centrosymmetric, dimeric molecules with a planar Cu2 Cl2 ring (Cu-CI bond lengths 229 and 231 pm). A terminally bonded CI atom (Cu-CI = 221 pm) and the N atom of the Me3SiNPPh3 ligand (Cu-N = 198.5 pm) complete the coordination number four of the nearly planar surroundings of the Cu atoms.

STEREOCHEMISTRY OF ARSENIC: PART XII. BIS(DIPHENYLARSENIC) OXIDE

1963 ◽  
Vol 41 (12) ◽  
pp. 2983-2987 ◽  
Author(s):  
W. R. Cullen ◽  
J. Trotter
Keyword(s):  
Unit Cell ◽  
The Other ◽  
Space Group ◽  
Bond Lengths ◽  
Valency Angle

Crystals of bis(diphenylarsenic) oxide are monoclinic, with four molecules in a unit cell of dimensions a = 11.48, b = 30.2, c = 5.97 Å, β = 93.8°, space group P21/n. The structure has been determined from projections along the a and c axes, using Fourier and difference syntheses. The As—O—As angle is 137°, the increase from the normal oxygen valency angle probably being a result of pπ—dπ bonding involving arsenic 4d orbitals. The As—O distance is 1.67 Å, and all the other bond lengths and angles are normal. The orientations of the substituent phenyl groups have been determined.

THE CRYSTAL STRUCTURE OF 1,4-DIBROMONAPHTHALENE

1961 ◽  
Vol 39 (8) ◽  
pp. 1574-1578 ◽  
Author(s):  
J. Trotter
Keyword(s):  
Crystal Structure ◽  
Detailed Examination ◽  
Unit Cell ◽  
Asymmetric Unit ◽  
Space Group ◽  
Bond Lengths ◽  
Sufficient Precision ◽  
Molecular Dimensions

Crystals of 1,4-dibromonaphthalene are monoclinic with eight molecules in a unit cell of dimensions a = 27.45, b = 16.62, c = 4.09 Å; β = 91.9°; space group P21/a The high proportion of bromine in the crystal probably precludes location of the carbon atoms with sufficient precision to give accurate molecular dimensions, and it has therefore not been considered worth while proceeding beyond the detailed examination of the projection along the short c-axis. There are two molecules in the asymmetric unit, and the solution of the structure from hk0 Patterson and Fourier projections has indicated that these two molecules are related, at least in projection, by a pseudo center of symmetry. The projected bond distances indicate significant deviations of the bromine atoms from the aromatic plane. Approximate values of the bond lengths in the molecule have been deduced from the projected distances and estimated orientation angles.

Barium-Triel-Mercuride BaMxHg4-x und Ba3MxHg11-x (M=Ga, In, Cd) / Barium Triel Mercurides BaMxHg4-x and Ba3MxHg11-x (M =Ga, In, Cd)

2013 ◽  
Vol 68 (4) ◽  
pp. 307-322 ◽  
Author(s):  
Marco Wendorff ◽  
Caroline Röhr
Keyword(s):  
Ternary System ◽  
Theoretical Study ◽  
Structure Type ◽  
Unit Cell ◽  
Partial Ordering ◽  
Space Group ◽  
Bond Lengths ◽  
Type Orthorhombic ◽  
Stability Ranges ◽  
Phase Width

The systematic experimental and bond-theoretical study of the phase width of the BaAl4 structure type in the ternary system BaIn4- BaHg4 shows that this structure type is stable up to BaIn1:7Hg2:3 (tetragonal, tI10, space group I4=mmm, a=474.2(3), c=1228.7(9) pm, R1=0.0529). The planar 44 layers (M(2) site) are preferentially formed by In, whereas Hg occupies the tips (M(1) site) of the [M(1)M(2)4] square pyramids. The layers of the pyramids are connected via short M(1)-M(1) dumbbells (bonds a). The analysis of the calculated band structures of BaIn2Hg2 in comparison to BaIn4 and RbIn4 shows that contributions of Ba-d states (which are missing for RbIn4) and Hg-d states (which are missing in the pure indides) are significant. The respective compound with the smaller triel gallium (Hg-richest phase: BaGa1:9Hg2:1, tetragonal, oI40, space group I41=amd, a=671.3(2), c=2220.4(8) pm, Z =8, R1=0.0641) forms a new superstructure of the BaAl4 structure with a partial ordering of three statistically occupied mixed Ga=Hg positions. The 44 nets are formed by an intermediate proportion of Ga=Hg. The tips of the pyramids are alternately formed by a Ga- and an Hg-rich position leading to smaller and larger bond lengths a’ and a”, respectively, between the tip atoms and, consequentely, a puckering of the 44 net. The two Hg-rich 3 : 11 compounds Ba3InHg10 and Ba3CdHg10 (orthorhombic, oI28, space group Immm, a=513.96(8)=511.50(2), b=993.8(2)=991.54(3), c=1500.7(3)=1499.26(5) pm, Z =2, R1=0.0619=0.0482) crystallize in the La3Al11 structure type, which is also observed for K3Hg11 and is closely related to the BaAl4 type: The square pyramidal nets are corrugated leading to a triplication of the BaAl4 unit cell along one of the tetragonal axes. In each third subcell the tips of adjacent pyramids are directly fused, this position being occupied exclusively by In and Cd. With the smaller triel gallium, the 3 : 11 compound Ba3Ga0:2Hg10:8 crystallizes in the Ba3ZnHg10 structure type (orthorhombic, oP28, space group Pmmn, a=709.36(4), b=1707.96(9), c=630.78(4) pm, Z =2, R1=0.0342). The structure contains folded layers of flat rectangular Ga=Hg pyramids, leaving large channels at the folds, in which Ba(1) and Hg(2) atoms alternate. The formation and stability ranges of 1 : 4, 3 : 11 and related 5 : 19 trieles/mercurides are discussed taking geometric, electronic and M13=Hg ,coloring‘ aspects into account.

The crystal structures of CeSiO4 and Ca2Ce8(SiO4)6O2

2000 ◽  
Vol 15 (4) ◽  
pp. 234-238 ◽  
Author(s):  
J. M. S. Skakle ◽  
C. L. Dickson ◽  
F. P. Glasser
Keyword(s):  
Hydrothermal Synthesis ◽  
Nuclear Waste ◽  
Structure Type ◽  
Unit Cell ◽  
Apatite Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Zircon Structure

Two new solubility-limiting phases relevant to nuclear waste disposal are reported, namely CeSiO4 and Ca2Ce8(SiO4)O2, produced by hydrothermal synthesis at 180 °C. X-ray diffraction data are presented for both compounds. Rietveld refinement was performed for each of these phases. CeSiO4 was confirmed to be a zircon structure type, with space group I41/amd, unit cell type="bold">abold=6.9564(3), type="bold">cbold=6.1953(4) Å. Bond lengths for SiO4 are in excellent agreement with published values; Ce4+ is coordinated to eight oxygen atoms with four regular and four short bonds. Ca2Ce8(SiO4)O2 was shown to have an apatite structure, with space group P63/m and unit cell type="bold">abold=9.4343(3), type="bold">cbold=6.8885(4) Å. The unit cell and bond lengths were found to be slightly smaller than would be expected from other lanthanide-containing analogs; possible reasons for this are discussed.

Cu6Br6(NPMe3)4, ein gemischt-valenter Kupfercluster / Cu6Br6(NPMe3)4, a Mixed-Valent Cluster of Copper

1994 ◽  
Vol 49 (7) ◽  
pp. 987-990 ◽  
Author(s):  
Rolf Meyer zu Köcker ◽  
Kurt Dehnicke ◽  
Dieter Fenske
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Bromine Atom ◽  
Unit Cell ◽  
Crystal Structure Determination ◽  
Space Group ◽  
Bond Lengths ◽  
Cluster Molecule

Abstract Cu6Br6(NPMe3)4 has been prepared as a by-product from the reaction of CuBr with Me3SiNPMe3 in a CH2Cl2 suspension. The dark red-violet crystals, which contain three molecules CH2Cl2 per unit cell, have been characterized by a crystal structure determination. Cu6Br6(NPMe3)4 · 3 CH2Cl2: Space group P1̅, Z = 2, lattice dimensions at -95 °C: a = 1165.2(4), b = 1168.9(4), c = 1842.9(6) pm, a = 75.61(3)°, β = 84.15(3)°, γ = 61.08(2)°, 6918 observed unique reflections, R = 0.066. In the cluster molecule Cu6Br6(NPMe3)4 the copper atoms form a nearly ideal octahedron with Cu-Cu bond lengths of 268.8 pm in average. Each of the Cu atoms is con­nected with a terminal bromine atom. Four planes of the octahedron are capped by μ3-nitrogen atoms of the (NPMe3)- groups.

Crystal Structure of Tetrabutylammonium Carbonyltribromoplatinate(II) [(C4H9)4N][PtBr3(CO)]

2002 ◽  
Vol 57 (6) ◽  
pp. 610-614 ◽  
Author(s):  
Michael Berkei ◽  
Jamie F. Bickley ◽  
Brian T. Heaton
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Unit Cell ◽  
Monoclinic System ◽  
Space Group ◽  
Bond Lengths

AbstractTetrabutylammonium carbonyltribromoplatinate(II) [(C4H9)4N][PtBr3(CO)] crystallises in the monoclinic system in the space group P21/n with a = 1487.84(13), b = 897.41(8), c = 1849.6(2) pm, β = 106.558(2)° and four formula units per unit cell. The [PtBr3 (CO)]- anion is symmetrical (C2v) and almost planar with Pt-Br bond lengths of 242.40(12) pm (trans to CO), 243.25(10) pm and 242.99(9) pm (trans to Br), and a Pt-C bond length of 185.6(11) pm.

Crystal structure of Cu3(AsO4)2

1968 ◽  
Vol 46 (6) ◽  
pp. 917-927 ◽  
Author(s):  
Sandra J. Poulsen ◽  
C. Calvo
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Bond Distance ◽  
Unit Cell ◽  
Monoclinic Crystal ◽  
Space Group ◽  
Bond Lengths ◽  
Oxygen Distance ◽  
Atom Bond ◽  
Oxygen Atoms

Cu3(AsO4)2 forms a monoclinic crystal with lattice parameters a = 6.327(5) Å, b = 8.642(5) Å, c = 11.313(5) Å, β = 92.04(4)°, and Z = 4. The space group is P21/c. The two orthoarsenate anions in the unit cell have average AsO bond lengths of 1.68 Å and 1.70 Å with mean deviations of 0.02 Å and 0.01 Å respectively. The three cations are fivefold coordinated to oxygen atoms with mean cation oxygen atom bond lengths of 2.005 Å, 2.053 Å, and 2.017 Å for the three independent cations. The range of bond distances extends from 1.892 Å to 2.362 Å. Only one additional cation oxygen distance of less than 3 Å occurs and this lies at 2.76 Å. The cation polyhedra form sheets parallel to the ab plane by corner and edge sharing of common oxygen atoms. Adjacent sheets are bonded through the long Cu—O bond distance cited above and by the AsO43− anions. Each of the arsenic atoms shares three oxygen atoms with one sheet and one with the adjacent one.

Die Struktur des 2.3.4.6.7.8-Hexamethyl-2.3.4.6.7.8-hexaphosphabicyclo- [3.3.0] octans (PMe)6C2H2 / The Structure of 2,3,4,6,7,8-Hexamethyl-2,3,4,6,7,8-hexaphosphabicyclo[3,3,0]octane (PMe)6C2H2

1978 ◽  
Vol 33 (7) ◽  
pp. 698-701 ◽  
Author(s):  
Hans-Georg von Schnering ◽  
Wolfgang May
Keyword(s):  
Chair Conformation ◽  
Molecular Packing ◽  
Unit Cell ◽  
Methyl Groups ◽  
Trans Conformation ◽  
Space Group ◽  
Bond Lengths ◽  
Bicyclic System ◽  
The Mean ◽  
Independent Molecules

Abstract One of the diastereomeres of 2,3,4,6,7,8-hexamethyl-2,3,4,6,7,8-hexaphosphabicyclo-[3,3,0]octane (PMe)6C2H2 crystallizes in the space group P21/n with four molecules per unit cell. Two independent molecules are nearly identical in shape but differ by inter-molecular packing. The five-membered rings have a skew chair conformation with all exocyclic methyl groups in axial positions leading to a staggered all-trans conformation of the bicyclic system. The mean bond lengths are P-P = 220.9 pm, P-C = 185.9 pm and C-C = 151.9 pm.

STEREOCHEMSTRY OF ARSENIC: PART III. o-PHENYLENEDIARSINE OXYCHLORIDE

1962 ◽  
Vol 40 (6) ◽  
pp. 1113-1117 ◽  
Author(s):  
W. R. Cullen ◽  
J. Trotter
Keyword(s):  
Symmetry Axis ◽  
Van Der Waals ◽  
Membered Ring ◽  
Unit Cell ◽  
The Other ◽  
Van Der Waals Interactions ◽  
Chlorine Atoms ◽  
Space Group ◽  
Bond Lengths ◽  
Aromatic Character

Crystals of o-phenylenediarsine oxychloride, C6H4As2Cl2O, are monoclinic with four molecules in a unit cell of dimensions a = 14.50, b = 8.38, c = 7.66 Å, β = 105.8°, space group C2/c. The structure has been determined from projections along the b and c axes. Each molecule is situated on a 2-fold symmetry axis and is planar except for the chlorine atoms, which lie one on either side of the plane of the other atoms. The values of the bond lengths and valency angles have been obtained. Abnormal valency angles at the arsenic and oxygen atoms are the result of their presence in the five-membered ring, and the unusual stability of the molecule in spite of these angles can be interpreted in terms of aromatic character, involving dπ–pπ bonding. The intermolecular separations correspond to normal van der Waals interactions.

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