Conformational analysis of coordination compounds. XIII. Complexes of 2-methylpentane-2,4-diamine

1981 ◽  
Vol 34 (12) ◽  
pp. 2525 ◽  
Author(s):  
TW Hambley ◽  
CJ Hawkins ◽  
JA Palmer ◽  
MR Snow
Keyword(s):  
Chelate Ring ◽  
Cobalt Complex ◽  
Platinum Complex ◽  
Chair Conformation ◽  
Geometrical Parameters ◽  
Boat Conformation ◽  
Space Group ◽  
X Ray ◽  
Strain Energy Minimization ◽  
Good Agreement

The crystal structures of tetraammine{(�)-2-methylpentane-2,4-diamine} cobalt(III) tetrachlorozincate chloride and 2,2'-bipyridine{(�)-2-methylpentane-2,4-diamine)platinum(II) nitrate semihydrate have been determined by X-ray structure analysis. The former crystals are orthorhombic with the space group P212121, with a 12.49, b 20.16 and c 7.68 �. The latter crystals are also orthorhombic but with the space group Pbca with a 14.96, b 28.69 and c 19.45 �. Both structures have been refined by least-squares methods to weighted R values of 0.034 (1407 reflections) and 0.055 (2301 reflections), respectively. The six-membered diamine chelate ring has a flattened chair conformation in the cobalt complex, and an unsymmetric boat conformation in the platinum complex. Strain-energy-minimization calculations show these structures correspond to energy minima and the calculated geometrical parameters are in good agreement with those observed for the chelate ring. Proton n.m.r. spectra are consistent with the chair conformation being almost exclusively populated in the ammine complex and in the tetracyanocobaltate(III) complex in aqueous solution, but the and 13C n.m.r. spectra of the platinum(II) complex show that, although the chair conformer predominates, the boat conformation is significantly populated in solution.

Conformational analysis of coordination compounds. XI. Molecular structure of tetraammine{(±)-pentane-2,4-diamine)cobalt(III) dithionate

1981 ◽  
Vol 34 (1) ◽  
pp. 45 ◽  
Author(s):  
TW Hambley ◽  
CJ Hawkins ◽  
JA Palmer ◽  
MR Snow
Keyword(s):  
Conformational Analysis ◽  
Chelate Ring ◽  
Minimum Energy ◽  
Chair Conformation ◽  
Energy Difference ◽  
Boat Conformation ◽  
Anisotropic Temperature ◽  
Strain Energy Minimization ◽  
Temperature Factors ◽  
Good Agreement

The crystal structure of tetraammine{(�)-pentane-2,4-diamine}cobalt(III) dithionate dihydrate [Co{(�)-ptn}(NH3)4] (S2O6)1.5,2H2O has been determined by X-ray structure analysis. The crystals are triclinic with the space group Pī, with a 11.43, b 11.65, c 7.78 �, α 100.48�, β 105.95�, and γ 75.95�. The structure has been refined by least-squares methods with anisotropic temperature factors to an R value of 0.043 for 2654 reflections. The six-membered diamine chelate ring has a skew-boat conformation in which the two methyl groups are in equatorial orientations. A strain- energy-minimization calculation for the complex reveals an energy difference of 8.3 kJ mol-l between the preferred skew-boat conformation and the chair conformation. The calculated minimum-energy geometry for the skew-boat conformation is in good agreement with the observed structure for the chelate ring in the dithionate salt. The lH N.M.R. spectra of this complex and other complexes of the chiral isomer of pentane-2,4-diamine are discussed in terms of the observed structures and the conformational analysis.

Crystal structure determination of the conformation of two bicyclo[3.3.1]nonan-ones

1985 ◽  
Vol 63 (6) ◽  
pp. 1166-1169 ◽  
Author(s):  
John F. Richardson ◽  
Ted S. Sorensen
Keyword(s):  
Crystal Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Final Agreement

The molecular structures of exo-7-methylbicyclo[3.3.1]nonan-3-one, 3, and the endo-7-methyl isomer, 4, have been determined using X-ray-diffraction techniques. Compound 3 crystallizes in the space group [Formula: see text] with a = 15.115(1), c = 7.677(2) Å, and Z = 8 while 4 crystallizes in the space group P21 with a = 6.446(1), b = 7.831(1), c = 8.414(2) Å, β = 94.42(2)°, and Z = 2. The structures were solved by direct methods and refined to final agreement factors of R = 0.041 and R = 0.034 for 3 and 4 respectively. Compound 3 exists in a chair–chair conformation and there is no significant flattening of the chair rings. However, in 4, the non-ketone ring is forced into a boat conformation. These results are significant in interpreting what conformations may be present in the related sp2-hybridized carbocations.

The Dichloroplatinum(II) and Dichloropalladium(II) Complexes of 1,4-Diazacycloheptane: Preparative, Structural and Conformational Studies

1996 ◽  
Vol 49 (12) ◽  
pp. 1301 ◽  
Author(s):  
GW Allen ◽  
ECH Ling ◽  
LV Krippner ◽  
TW Hambley
Keyword(s):  
Crystal Structures ◽  
Chelate Ring ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Membered Chelate Ring ◽  
Alternative Conformation

The preparation and purification of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] ( hpip = homopiperazine = 1,4-diazacycloheptane) are described. Crystal structures of [Pt( hpip )Cl2] and [Pd( hpip )Cl2] have been determined by X-ray diffraction methods and refined to R values of 0.023 (932 F) and 0.023 (948 F). The crystals of [Pt( hpip )Cl2] are orthorhombic, space group Pbcm , a 7.7019(8), b 9.8080(12), c 12.1944(14) Ǻ, and those of [Pd( hpip )Cl2] are monoclinic, space group P21/m, a 6.1001(9), b 11.527(2), c 6.458(I) Ǻ, β 106.30(2)°. The seven- membered rings of the ligands in both complexes adopt boat-like conformations in which the five- membered chelate ring has an eclipsed N-C-C-N group and the six- membered chelate ring adopts a chair conformation. Molecular mechanics methods were used to investigate whether this conformation was a crystallographic artefact but it was found to be real. An alternative conformation in which the six-membered chelate ring adopts a skew-boat conformation was also investigated. It was found to be less stable than the conformation observed in the crystal structures, but to a degree that depends on whether non-bonded interactions involving the metal atom were included or not.

Structural Studies of Seven Compounds of Cobalt(III) With trans-6,13-Diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane

1992 ◽  
Vol 45 (10) ◽  
pp. 1663 ◽  
Author(s):  
NF Curtis ◽  
WT Robinson ◽  
DC Weatherburn
Keyword(s):  
Chelate Ring ◽  
Chair Conformation ◽  
Boat Conformation ◽  
Structural Studies ◽  
Molecular Plane ◽  
X Ray ◽  
Membered Chelate Ring ◽  
Additional Ligand ◽  
Primary Amino ◽  
Amine Groups

The structures of seven compounds of trans-6,13-diamino-6,13-dimethyl-1,4,8,11-tetraacyclotetradecane (diam) with cobalt(III) have been determined by X-ray diffractometry: (1), trans-α-[{Co(diam-N5)}2(O2)](ClO4)4.2H2O (monoclinic, P21/n, a 10.673(2), b 22.924(8), c 19.332(5) Ǻ,β 114 19(2)°, R 0.044 for 4547reflections); (2), trans-α-[Co(diam-N5)Cl](ClO4)2 (orthorhombic, P 212121, a 9.043(4), b 11.214(4), c 21.431(8) A, R 0.055 for 1541 reflections); (3), trans-α- Co(diamH-N5)Cl] [ZnCl4] Cl.H2O (orthorhombic, Pna 21, a 25.26(5), b 9.866(2), c 9.457(2) 1, R 0.108 for 1686 reflections); (4), trans-α-[Co(diamH-N5)(H2O)Cl3.ClO4 (monoclinic, P 21/n, a 12.928(8), b 8.554(5), c 20.624(12) A, β 106.00(4)°, R 0.060 for 2094 reflections); (5), trans-γ-[Co(diamH-N5)Cl]Cl3.3H2O (orthorhombic, P212121, a 12.895(7), b 12.898(9), c 13 -417(4) Ǻ, R 0.062 for 860 reflections); (6), trans-β-[Co(diamHN5) Cl] [ZnCl4]CI.½H2O.½C3.H7OH(triclinic, P1, a 10.469(4), b 9.167(5), c 15.464(6) Ǻ, α 73.74(4), β 71.15(3), γ 73.70(1)°, R 0.045 for 3685 reflections); (7), trans-β-[Co(diamH2- N4)Cl2] [ZnCl4]Cl.½H2O.½C2.H5OH(triclinic, P1, a 10.138(2), b 12.011(3), c 12-451(2) Ǻ, α 79,87(2), β 66.64(1), γ 66.64(1)°, R 0.035 for 2637 reflections). The cations of compounds (1)-(6) all have pentadentate diam (diam-N5 or diamH-N5) with one primary amino substituent coordinated trans to the additional ligand. Compounds (1)-(4) have the pentadentate macrocycle in cyclam configuration (1). R,S,R,S, with all four secondary amine groups on the same side of the molecular plane, with one six-membered chelate ring in a boat conformation with the amino substituent coordinated, and the other in a chair conformation. Compound (5) has the pentadentate macrocycle in configuration (2), R,R,S,R, with one NH group alone on one side of the molecular plane with the six-membered chelate ring with the non-coordinated amrnonio substituent in a skew conformation. Compounds (6) and (7) have the R,R,S,S configuration (S'), (6) having diamH-N5 with one amine substituent coordinated, and (7) with planar tetradentate diamH2-N4 in the macrocycle conformation usual for planar coordinated cyclam compounds, the ammonio substituents being equatorially oriented.

The X-Ray Crystal Structure of 1,2-3,4-Di-O-isopropylidene-4-C-methylthiomethoxy-β-L-arabino-hexoseptanos-5-ulose

1990 ◽  
Vol 43 (12) ◽  
pp. 2083 ◽  
Author(s):  
DC Craig ◽  
VJ James ◽  
JD Stevens
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Membered Ring ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

The crystal structure of the title compound (1) has been determined by X-ray diffraction. Crystals of (1) are orthorhombic, space group P21212 with a 11.425(1), b 24.916(1), c 5.8952(3)Ǻ, Z 4. Refinement on 1675 observed reflections measured with Cu Kα radiation converged at R 0.034. The seven- membered ring adopts a boat conformation in which the pseudo plane of symmetry passes through the ring oxygen.

The conformation of (1S,3S,4R)- 1,3,8-Tribromo-p-menthan-2-one

1983 ◽  
Vol 36 (5) ◽  
pp. 1043 ◽  
Author(s):  
RM Carman ◽  
E Horn ◽  
CHL Kennard ◽  
G Smith ◽  
MR Snow ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
A Cell ◽  
Twist Boat

The crystal structure of (1S,3S,4R)-1,3,8-tribromo-p-menthan-2-one has been determined from X-ray diffraction data and refined to a final residual of 0.075 for 635 'observed' reflections. Crystals are orthorhombic, of space group P212121 with four molecules in a cell of dimensions a 15.248(3), b 12.189(3), c 7.201(2) �. The analysis confirms that the molecule exists in a distorted twist-boat conformation.

scholarly journals Synthesis of Trithia-Borinane Complexes Stabilized in Diruthenium Core: [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BR}] (R = H or SMe)

Inorganics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 21 ◽  
Author(s):  
Koushik Saha ◽  
Urminder Kaur ◽  
Rosmita Borthakur ◽  
Sundargopal Ghosh
Keyword(s):  
Mass Spectrometry ◽  
1H Nmr Spectroscopy ◽  
Chair Conformation ◽  
Membered Ring ◽  
Molecular Structures ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Butterfly Cluster ◽  
Tellurium Powder

The thermolysis of arachno-1 [(Cp*Ru)2(B3H8)(CS2H)] in the presence of tellurium powder yielded a series of ruthenium trithia-borinane complexes: [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BH}] 2, [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3B(SMe)}] 3, and [(Cp*Ru)2(η1-S)(η1-CS){(CH2)2S3BH}] 4. Compounds 2–4 were considered as ruthenium trithia-borinane complexes, where the central six-membered ring {C2BS3} adopted a boat conformation. Compounds 2–4 were similar to our recently reported ruthenium diborinane complex [(Cp*Ru){(η2-SCHS)CH2S2(BH2)2}]. Unlike diborinane, where the central six-membered ring {CB2S3} adopted a chair conformation, compounds 2–4 adopted a boat conformation. In an attempt to convert arachno-1 into a closo or nido cluster, we pyrolyzed it in toluene. Interestingly, the reaction led to the isolation of a capped butterfly cluster, [(Cp*Ru)2(B3H5)(CS2H2)] 5. All the compounds were characterized by 1H, 11B{1H}, and 13C{1H} NMR spectroscopy and mass spectrometry. The molecular structures of complexes 2, 3, and 5 were also determined by single-crystal X-ray diffraction analysis.

Structure cristalline et moléculaire de l'acétoxy-3β ursane olide-28,20βa

1987 ◽  
Vol 65 (4) ◽  
pp. 851-854 ◽  
Author(s):  
Danielle Druet ◽  
Louis Claude Comeau ◽  
Robert Viani ◽  
André Baldy ◽  
Jacques Estienne ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Chemical Analysis ◽  
Chair Conformation ◽  
Boat Conformation ◽  
X Ray ◽  
Crystallographic Study

An X-ray crystallographic study of the triterpene C32H50O4, isolated from Opiliaceltidifolia, confirms the chemical analysis of the molecular structure. The rings A, B, C, and D are in the chair conformation, but ring E, due to a bridging lactone between the C(17) and C(20) carbon atoms, adopts a boat conformation. All five six-membered rings are trans-fused.

Synthesis and structural characterization of donor-stabilized disubstituted diphenyldithiophosphates of nickel(II)

2014 ◽  
Vol 70 (4) ◽  
pp. 761-767 ◽  
Author(s):  
Sandeep Kumar ◽  
Ruchi Khajuria ◽  
Amanpreet Kaur Jassal ◽  
Geeta Hundal ◽  
Maninder S. Hundal ◽  
...  
Keyword(s):  
Single Crystal ◽  
Chelate Ring ◽  
Donor Ligands ◽  
Monoclinic Space Group ◽  
Bidentate Ligands ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray

Donor-stabilized addition complexes of nickel(II) with disubstituted diphenyldithiophosphates, [{(ArO)2PS2}2NiL2] {Ar = 2,4-(CH3)2C6H3[(1), (5)], 2,5-(CH3)2C6H3[(2), (6)], 3,4-(CH3)2C6H3[(3), (7)] and 3,5-(CH3)2C6H3[(4), (8)];L= C5H5N [(1)–(4)] and C7H9N [(5)–(8)]}, were successfully isolated and characterized by elemental analysis, magnetic moment, IR spectroscopy and single-crystal X-ray analysis. Compound (4) crystallizes in the monoclinic space groupP21/nwhereas compounds (7) and (8) crystallize in the triclinic space group P\bar 1. The single-crystal X-ray diffraction analysis of (4), (7) and (8) reveals a six-coordinated octahedral geometry for the NiS4N2chromophore. Two diphenyldithiophosphate ions act as bidentate ligands with their S atoms coordinated to the Ni centre. Each of them forms a four-membered chelate ring in the equatorial plane. The N atoms from two donor ligands are axially coordinated to the Ni atom.

Tetramethyld-η2-vinyldisiloxan(triphenylphosphan)platin(0) / Tetramethyldi-η2-vinyldisiloxane(triphenylphosphine)platinum(0)

1991 ◽  
Vol 46 (12) ◽  
pp. 1694-1698 ◽  
Author(s):  
Georg Beuter ◽  
Olga Heyke ◽  
Ingo-Peter Lorenz
Keyword(s):  
Crystal Structure ◽  
Chair Conformation ◽  
Ring System ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The reaction of (Ph3P)2PtC2H4 with the divinyldisiloxane (CH2=CHSiMe2)2O in toluene yields Pt{(η2-H2C=CHSiMe2)2O}PPh3, which has been characterized by IR, 1H, 13C, 31P NMR and MS spectra. The crystal structure was determined by X-ray diffraction: space group C2/c, Z = 16, a = 5534.2(9), b = 842.6(2), c = 2383.1(2) pm, β = 103.73(1)°, R/Rw = 0.047/0.052. It shows a three-coordinate platinum atom with one phosphine and one sym-tetramethyldivinyldisiloxane ligand acting as a chelating bidentate η/2-ligand to give a chair conformation of the six-membered PtC2Si2O-ring system.

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