Crystal structure of N,N′-dimethyl-2-imidazolidinethione, a by-product from the reaction of Na2(CH2N(CH3)CS2)2 and HgCl2

1983 ◽  
Vol 61 (1) ◽  
pp. 211-213 ◽  
Author(s):  
Chung Chieh ◽  
Sing Kwen Cheung
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Least Squares ◽  
Aqueous Ethanol ◽  
Ethanol Solution ◽  
Aqueous Ethanol Solution ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
Space Group ◽  
Automatic Diffractometer

The reaction between mercury (II) chloride and N,N′-dimethylethylenebisdithiocarbamate gave a white precipitate. In an attempted recrystallization from an aqueous–ethanol solution, a cyclic thiourea-type compound, N,N′-dimethyl-2-imidazolidinethione, was obtained. The crystals of this compound are monoclinic, a = 10.388(2), b = 6.139(1), c = 12.291(4) Å, β = 118.64(2), and space group P21/c. The non-hydrogen atoms of the molecule are planar and the C=S bond length is 1.673(4) Å. The structure was refined by full-matrix least-squares from 642 independent reflections measured on an automatic diffractometer to R and Rw of 0.053 and 0.068, respectively.

The preparation and crystal structure of η2-nitrato(η4-hexadecamethylcyclooctaphosphazene (N1,N2,N4,N5))cobalt(II) nitrate

1981 ◽  
Vol 59 (16) ◽  
pp. 2435-2440 ◽  
Author(s):  
Keith D. Gallicano ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Least Squares ◽  
Cobalt Atom ◽  
Direct Methods ◽  
Nitrate Anion ◽  
Hydrogen Atoms ◽  
Nitrate Ion ◽  
Full Matrix ◽  
Local Conformation

Hexadecamethylcyclooctaphosphazene N8P8Me16, 1, forms a 1:1 complex, 2, with cobalt(II) nitrate. Crystals of 2 are triclinic, a = 10.891(2), b = 11.201(2), c = 14.944(2) Å, α = 93.21(1), β = 95.66(1), γ = 104.69(1)°, Z = 2, space group [Formula: see text]. The crystal structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.037 and Rw = 0.047 for 5165 reflections with I ≥ 3σ(I). All the hydrogen atoms were found. The structure consists of a cation [N8P8Me16CoNO3]+ and a free nitrate anion. The cobalt atom is coordinated by an unsymmetrical bidentate nitrate ion and by four nitrogen atoms of the phosphazene ring. The metal is attached near one end of the ring, forming six-, ten-, and two four-membered chelate rings, and induces bond length variations which are independent of local conformation and which arise from the localization of bonding electrons.

Crystal Structure of Synthetic Mg-Whitlockite, Ca18Mg2H2(PO4)14

1974 ◽  
Vol 52 (7) ◽  
pp. 1155-1164 ◽  
Author(s):  
Ramanathan Gopal ◽  
Crispin Calvo ◽  
Jun Ito ◽  
W. K. Sabine
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Formula Unit ◽  
Full Matrix ◽  
Space Group ◽  
R Value ◽  
Unit Density ◽  
A Chain ◽  
Automatic Diffractometer

Crystals of synthetic Mg-whitlockite, Ca18Mg2H2(PO4)14, have been grown by hydrothermal techniques and their structure refined by full-matrix least-squares methods, using 1626 unique reflections measured with a Syntex [Formula: see text] automatic diffractometer, to a final R value of 0.046. The crystals have space group R3c with ZR = 1, a = 13.765(8) Å and α = 44.25(5)° with the equivalent hexagonal parameters a = 10.350(5), c = 37.085(12) Å and ZH = 3. The structure, although similar to that of βCa3(PO4)2, differs significantly. The structure contains interconnected infinite chains of polyhedra paralleling the hexagonal c axis with links in the chains consisting of three CaO8 polyhedra separated by two PO4 tetrahedra. Six of these chains surround a chain of MgO6 octahedra and PO4H groups which lie on the three-fold axes. These chains however contain only half the formula unit density of the calcium containing ones and a proton, presumably disordered, is attached to the oxygen atom on the triad axes.

Crystal Structure of the Glaserite Form of BaNaPO4

1975 ◽  
Vol 53 (12) ◽  
pp. 1849-1853 ◽  
Author(s):  
Crispin Calvo ◽  
Romolo Faggiani
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Least Squares ◽  
Coordination Number ◽  
Cation Site ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
R Value ◽  
Cation Sites

Crystals of BaNaPO4 were grown from a Ba3P2O8–Na2B4O7 melt. The crystals are trigonal, space group [Formula: see text]with a = 5.622(4) and c = 7.259(5) Å. The structure, isotypic with that of glaserite, was refined by full-matrix least-squares methods to a final R value of 0.042 using 218 unique reflections. There are three different cation sites. Na and Ba lie at sites of [Formula: see text] symmetry and are coordinated to 6 and 12 oxygen atoms respectively. The Na—O bond lengths are 2.344(7) Å and the two unique Ba—O bond lengths are 2.788(7) and 3.247(9) Å. The remaining cation site has 3m symmetry, a coordination number of 10, and contains equal amounts of Na+ and Ba2+. The bond lengths range from 2.548(12) to 3.017(7) Å. The phosphate group also has 3m symmetry with mean P—O bond lengths of 1.538 Å. The underbonded apical P—O bond length is 1.520 Å.

The crystal structure and vibrational spectra of cis-dichlorobis(cyclopropylamine)-platinum(II), PtCl2(C3H5NH2)2

1981 ◽  
Vol 59 (18) ◽  
pp. 2737-2745 ◽  
Author(s):  
Helen Elaine Howard-Lock ◽  
Colin James Lyne Lock ◽  
Graham Turner ◽  
Maruta Zvagulis
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Vibrational Spectra ◽  
Vibrational Analysis ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Deuterated Analogue

Crystals of cis-dichlorobis(cyclopropylamine)platinum(II), PtCl2(C3H5NH2)2, are monoclinic, a = 12.770(5), b = 5.838(2), c = 15.113(6) Å, β = 104.46(3)°, Z = 4, space group P21/c. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares to R = 0.057, Rw = 0.055 for 1577 reflections with I > 3σ(I). Bond lengths and angles are normal. A vibrational analysis of the compound and its d2-deuterated analogue was performed.

The crystal structure of kogarkoite, Na3SO4F

1980 ◽  
Vol 43 (330) ◽  
pp. 753-759 ◽  
Author(s):  
L. Fanfani ◽  
G. Giuseppetti ◽  
C. Tadini ◽  
P. F. Zanazzi
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Thermal Parameters ◽  
Cell Content ◽  
Space Group ◽  
X Ray ◽  
Structural Relationships ◽  
Automatic Diffractometer ◽  
Monoclinic Cell

SummaryThe crystal structure of synthetic kogarkoite has been determined from X-ray data collected on an automatic diffractometer. The refinement was performed by a least-squares method employing anisotropic thermal parameters. The 3157 reflections with I > 3σ(I) converged to a conventional R value of 0.033. The cell content is 12 Na3SO4F, the space-group P21/m, a = 18.074, b = 6.958, c = 11.443 Å, β = 107.71°.Kogarkoite presents a marked trigonal subcell with c′ corresponding to [102] of the monoclinic cell. The tridimensional framework can be considered built up by nine differently stacked layers of Na atoms approximately perpendicular to the c′ axis (five sheets are present in galeite, six in sulphohalite, and seven in schairerite). The very close structural relationships between these minerals are discussed.

Reaction of N,N′-dihydroxy-.N,N′-dimethylmethanediamine with phenylboronic acid and the crystal and molecular structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine

1989 ◽  
Vol 67 (11) ◽  
pp. 1959-1963 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Exact Formula ◽  
Full Matrix ◽  
Space Group ◽  
Hydrogen Bonded

The reaction of N,N′-dihydroxy-N,N′-dimethylmethanediamine with phenylboronic acid leads to the product 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane rather than the expected product 1,5-dimethyl-3-phenyl-1,5-diaza-2,4-dioxa-3-boracyclohexane. The structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine has been determined and is discussed in terms of its reaction with PhB(OH)2. Crystals of N,N′-dihydroxy-N,N′-dimethylmethanediamine are tetragonal, a = 8.5346(3), c = 8.4178(7) Å, Z = 4, space group P421c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.036 and Rw of 0.038 for 333 reflections with I ≥ 3σ(I). The structure consists of hydrogen-bonded dimers having exact [Formula: see text] symmetry. Keywords: N,N′-dihydroxy-N,N′-dimethylmethanediamine, crystal structure.

The Crystal Structure of Dimedone

1975 ◽  
Vol 53 (7) ◽  
pp. 1046-1050 ◽  
Author(s):  
Ishwar Singh ◽  
Crispin Calvo
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Direct Methods ◽  
Monoclinic Symmetry ◽  
Enolic Form ◽  
Full Matrix ◽  
Space Group ◽  
Least Squares Techniques

Dimedone, C8H12O2, crystallizes with monoclinic symmetry, a = 10.079(7), b = 6.835(3), c = 12.438(4) Å, β = 110.24(5)°, space group P21/n and Z = 4. The structure of this compound was solved by direct methods and refined by full-matrix least-squares techniques using 1205 unique reflections to a final R of 0.047. In the solid state it exists in the enolic form and these molecules pack in the crystal in systems of infinite chains linked together by hydrogen bonds in the y direction. These results are virtually the same as recently reported by Semmingsen.

Refinement of the structure of Mg2As2O7

1970 ◽  
Vol 48 (6) ◽  
pp. 890-894 ◽  
Author(s):  
C. Calvo ◽  
K. Neelakantan
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Unit Cell ◽  
Full Matrix ◽  
Space Group ◽  
Cell Dimensions ◽  
Central Oxygen ◽  
R Value ◽  
Unit Cell Dimensions

The crystal structure of Mg2As2O7 has been refined by full matrix least squares procedures using 587 observed reflections. The structure of Mg2As2O7 is of the thortveitite type, as reported by Łukaszewicz, with space group C2/m and unit cell dimensions a = 6.567(2) Å, b = 8.524(4) Å, c = 4.739(1) Å, β = 103.8(1)°, and Z = 2. The As—O—As group in the anion appears to be linear but the central oxygen atom undergoes considerable disorder in the plane perpendicular to this group. The AsO bond distances uncorrected for thermal motion are 1.67 Å for the As—O(—As) bond and 1.66 and 1.65 Å for the terminal As—O bonds. The final R value obtained is 0.088.

Crystal Structure of Adeninium Trichloromercurate(II),

1975 ◽  
Vol 53 (15) ◽  
pp. 2345-2350 ◽  
Author(s):  
Monique Authier-Martin ◽  
André L. Beauchamp
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Title Compound ◽  
Heavy Atom ◽  
Chloride Ions ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Space Group ◽  
Heavy Atom Method

The title compound belongs to space group P21/c with a = 23.99(1), b = 4.245(2), c = 25.98(1) Å, β = 117.58(7)°, and Z = 8. The structure was solved by the heavy-atom method and refined by block-diagonal least squares on 2589 independent observed reflections. All non-hydrogen atoms were refined anisotropically and some of the hydrogen atoms were located but their parameters were not refined. The final values of R and Rw were 0.042 and 0.047, respectively.The two nonequivalent mercury atoms have very similar environments. Two short Hg—Cl bonds (2.34–2.38 Å) at ∼ 165° define a quasi-molecular HgCl2 unit. Overall octahedral coordination is completed with two chloride ions at 2.76–2.84 Å and two chlorine atoms at 3.19–3.26 Å on neighboring HgCl2 quasi-molecules. HgCl6 octahedra share edges to form twofold ribbons in the b direction. This pattern of octahedra is identical with the onereported for β-NH4HgCl3. The cations are pairs of N(1)-protonated adenine molecules linked by two N(10)—H(10)… N(7) hydrogen bonds and stacked in the b direction. Water molecules act as acceptors in moderately strong hydrogen bonds with acidic protons H(1) and H(9) of adeninium ions. Other generally weaker hydrogen bonds exist between the various parts of the structure.

Crystal and molecular structure of L-prolinatodiphenylboron

1977 ◽  
Vol 55 (6) ◽  
pp. 958-965 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Conformational Disorder ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of L-prolinatodiphenylboron are monoclinic, a = 5.9427(5), b = 14.4633(7), c = 8.9654(4) Å, β = 98.423(8)°, Z = 2, space group P21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.037 and Rw of 0.053 for 1477 reflections with I ≥ 3σ(I). The proline ring exhibits conformational disorder. The crystal structure consists of discrete molecules linked by N—H … O hydrogen bonds (N … O = 2.893(3) Å) along the short a axis. Intramolecular N—B coordination occurs to form a system of two fused five-membered rings. Bond lengths (corrected for libration) are: N—B, 1.630(3), O—B, 1.529(3), O—C, 1.219(3) and 1.300(3), N—C, 1.506(3) and 1.507(3), C(sp3)–C(sp3), 1.525(4), C(sp2)—C(sp3), 1.517(3), and mean C—C(phenyl), 1.394 Å.

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