Lewis-Base-Dictated Structural Variations in Sodium Amide Chemistry: X-Ray Crystal Structures of Phenyl(2-pyridyl)amidosodium with Hexamethylphosphoric Triamide(HMPA) and with Pentamethyldiethylenetriamine(PMDETA)

1990 ◽  
Vol 29 (12) ◽  
pp. 1440-1441 ◽  
Author(s):  
Philip C. Andrews ◽  
William Clegg ◽  
Robert E. Mulvey
Keyword(s):  
Crystal Structures ◽  
Lewis Base ◽  
Structural Variations ◽  
Hexamethylphosphoric Triamide ◽  
X Ray ◽  
Sodium Amide

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LIX. Crystal Structure Determinations of Tetrakis(trimethylphosphine)copper(I) Halides and Tetrakis(triphenylphosphine)-copper(I) and -silver(I) Hexafluorophosphates

1990 ◽  
Vol 43 (10) ◽  
pp. 1697 ◽  
Author(s):  
GA Bowmaker ◽  
PC Healy ◽  
LM Engelhardt ◽  
JD Kildea ◽  
BW Skelton ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Structures ◽  
Lewis Base ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
Bond Lengths ◽  
Cu Complex ◽  
Structure Determinations

The crystal structures of [Cu(Pme3)4]X (X = Cl , Br, I) and of [M(PPh3)4] [PF6] (M = Cu, Ag) have been determined by single-crystal X-ray diffraction methods at 295 K. The former compounds contain nearly tetrahedral [Cu(PMe3)4]+ ions on sites of m symmetry with mean Cu-P bond lengths of 2.270, 2.271 and 2.278 Ǻ for X = Cl , Br and I respectively. The latter compounds contain [M(PPh3)4]+ ions on sites of 3 symmetry. In the M =Ag complex the coordination environment is close to tetrahedral, but in the M =Cu complex the length of the axial Cu-P bond [2.465(2)Ǻ] is significantly shorter than that of the off-axis bonds [2.566(2)Ǻ]. Possible reasons for this are discussed.

Lewis-Base Adducts of Group-1B Metal(I) Compounds. XXIII. Synthesis and Structures of the 'Tris(3,5-Dimethylpyridine)Copper(I) Halides, [(C7H9N)3CuX], X = Cl, Br, I

1986 ◽  
Vol 39 (7) ◽  
pp. 1043 ◽  
Author(s):  
JM Dyason ◽  
LM Engelhardt ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Total Loss ◽  
Lewis Base ◽  
Molecular Symmetry ◽  
X Ray ◽  
Ray Methods

The crystal structures of the title compounds, (C7H9N)3CuX, X = Cl , Br, I [(1), (2), (3)], have been determined by single-crystal X-ray methods at 295 K, being refined to residuals of 0.022, 0.053, 0.047 for 151, 312, 720 independent 'observed' reflections respectively. The three structures containing 3,5-dimethylpyridine have an interesting relationship in symmetry: (1) is rhombohedral , R3m, a 9.050(3)Ǻ, α 110.89(3)°, Z 1; (2) is rhombohedral, R3c, a 10.328(5)Ǻ, α 95.60(4), Z 2; and (3), derived from (2), is monoclinic, Cc, a 13.233(6), b 15.083(7), c 11.491(6)Ǻ, β 98.27(4)°, Z 4. The distances Cu- Cl , Br, I are 2.412(9), 2.51(1), 2.683(3)Ǻ, with Cu-N 2.08(1), 2.02(1), 1.98(2)- 2.15(4)Ǻ respectively. In (1), the symmetry of the molecule, containing pseudo- tetrahedrally coordinated copper, N3CuX, is a full 3 m, with the ligands lying in mirror planes containing the 3 axis; in (2), the ligands rotate about the Cu-N bonds so that the molecular symmetry is 3; and in (3) further distortion of this kind causes total loss of crystallographically imposed symmetry. This descent in symmetry is the converse of that observed in the rhombohedral series [(C6H7N)3CuX] (C6H7N = 3-methylpyridine), and the possible underlying reasons are explored in terms of intra- and inter-molecular X...H interactions.

Synthesis and X-ray Crystal Structures of the First Lewis Base-Stabilized, Monomeric Aluminum Stibides

2000 ◽  
Vol 19 (13) ◽  
pp. 2640-2642 ◽  
Author(s):  
Stephan Schulz ◽  
Martin Nieger
Keyword(s):  
Crystal Structures ◽  
Lewis Base ◽  
X Ray

Lewis-Base Adducts of Groups 11 Metal(I) Compounds. LXII. The Crystal Structures of the 1 : 1 Adducts of Copper(I) Chloride, Bromide and Thiocyanate With Quinoline

1991 ◽  
Vol 44 (8) ◽  
pp. 1049 ◽  
Author(s):  
PC Healy ◽  
BW Skelton ◽  
AF Waters ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Lewis Base ◽  
X Ray ◽  
Structure Determinations ◽  
The Subject ◽  
The Common

Adducts (1 : 1) of copper(I) chloride, bromide and thiocyanate with quinoline have been synthesized and have been the subject of single-crystal X-ray structure determinations at 295 K. Crystals of the chloride are orthorhombic, P 212121, a 15.358(7), b 14.309(6), c 3.801(2)Ǻ, Z 4; R was 0.055 for 541 'observed' reflections. Crystals of the bromide are monoclinic, C2/c, a 19.417(5), b 14.048(4), c 15.753(6) Ǻ, β 125.31(2)°, Z 4 tetramers; R was 0.049 for 1138 'observed' reflections. Crystals of the thiocyanate are monoclinic, P 21/c, a 5.682(1), b 10.412(2), c 16.838(5)Ǻ, β 97.48(2)°, Z 4 f.u .; R was 0.045 for 914 'observed' reflections. The chloride takes the form of the common 'stair' polymer, unexpectedly, while the thiocyanate is an expanded version of the same. The bromide provides a second example of a novel tetrameric 'basket' structure exemplified previously by the iodide analogue.

Lewis-base adducts of Group 1 metal(I) compounds. III. Synthesis and crystal structures of the 1 : 1 adducts of silver(I) iodide with triethylamine, 2- and 3-methylpyridine and quinoline

1983 ◽  
Vol 36 (9) ◽  
pp. 1851 ◽  
Author(s):  
PC Healy ◽  
NK Mills ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Unit Cell ◽  
Lewis Base ◽  
X Ray Diffraction ◽  
X Ray ◽  
Group 1

The crystal structures of the title compounds have been determined at 295(1) K by single-crystal X-ray diffraction methods. For [AgI(Et3N)] (1), the unit cell is tetragonal, P42/nmc, a 13.202(6),c 11.654(8) �; the structure was refined to a residual of 0.077 for 589 independent 'observed' reflections, and is isostructural with the 'pseudo-cubane' triethylphosphine and triethylarsineanalogues with two tetrameric units in the cell. For [AgI(2-MeC5H4N)] (2), the cell is orthorhombic,P212121, a 16.63(1), b 10.797(9), c 4.570(4) �, Z 4; a residual of 0.030 was obtained for 770 independent 'observed' reflections. For [AgI(3-MeC5H4N)] (3), the cell is monoclinic, P21/n, a 19.57(2), b 4.633(3), c 9.355(7) �, β 90.85(7)�, Z 4, a residual of 0.038 being obtained for 1382 independent 'observed' reflections. For [AgI(C9H7N)](4), the unit cell is monoclinic, P21/n, a 12.964(9), b 16.84(2), c 4.454(4) �, β 97.10(7)�, Z 4, a residual of 0.040 being obtained for 660 'observed' independent reflections. For compounds (2)-(4), the observed structures are all 'stairpolymers'; the structures of (2) and (3) are quite similar, but that of (4) exhibits significant differences.

Lewis-Base Adducts of Group-11 Metal(I) Compounds. XXIX. Crystal Structures of Bis(Pyridine-4-carbonitrile)silver(I) Nitrate and Bis(4-benzoylpyridine)Silver(I) Nitrate Monohydrate

1987 ◽  
Vol 40 (9) ◽  
pp. 1603 ◽  
Author(s):  
S Gotsis ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Least Squares ◽  
Crystal Structures ◽  
Complex Cation ◽  
Lewis Base ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Silver Atoms ◽  
Close Contacts

The crystal structures of the title compounds, [Ag(C6H4N2),] (NO3), (I), and [Ag(C12H9NO)2] (NO3).H2O, (2), have been determined by single-crystal X-ray diffraction methods at ~295 K, being refined by full-matrix least-squares methods to residuals of 0.042 and 0.044 for 1814 and 3434 independent 'observed' reflections respectively. Crystals of (1) and (2) are triclinic P1; for (1) a, 27.954(7), b 6.354(2), c 3.710(1)�, α 87.55(3), β 86.21(2), γ 89.35(2)�, Z 2; for (2), a 17.036(5), b 8.691(3), c 7.849(3) �, α � 107.74(2), β 97 53(2), γ 91 .11(2)�, Z 2. In both structures the formulation is basically a linearly coordinated complex cation/anion as shown above: in (I), Ag-N are 2.214(4), 2.203(4) � with N-Ag-N, 162.2(2)"; in (2), Ag-N are 2.146(3), 2.147(3) �, N-Ag-N, 175.3(1)�. The shortest Ag-O contact is found in (1) at 2.693(4)�. No close contacts are found between the silver atoms and cyano or ketonic ligand substituents.

Transmission electron microscope studies in special ceramics

1978 ◽  
Vol 36 (1) ◽  
pp. 268-269
Author(s):  
A. Zangvil ◽  
L.J. Gauckler ◽  
G. Schneider ◽  
M. Rühle
Keyword(s):  
Phase Diagrams ◽  
Crystal Structures ◽  
Thin Foil ◽  
Limited Extent ◽  
Complex Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Lattice Resolution

The use of high temperature special ceramics which are usually complex materials based on oxides, nitrides, carbides and borides of silicon and aluminum, is critically dependent on their thermomechanical and other physical properties. The investigations of the phase diagrams, crystal structures and microstructural features are essential for better understanding of the macro-properties. Phase diagrams and crystal structures have been studied mainly by X-ray diffraction (XRD). Transmission electron microscopy (TEM) has contributed to this field to a very limited extent; it has been used more extensively in the study of microstructure, phase transformations and lattice defects. Often only TEM can give solutions to numerous problems in the above fields, since the various phases exist in extremely fine grains and subgrain structures; single crystals of appreciable size are often not available. Examples with some of our experimental results from two multicomponent systems are presented here. The standard ion thinning technique was used for the preparation of thin foil samples, which were then investigated with JEOL 200A and Siemens ELMISKOP 102 (for the lattice resolution work) electron microscopes.

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