Compounds of the 16-Membered Macrocyclic Tetraamine (4RS,12RS)-2,2,4,10,10,12-Hexamethyl-1,5,9,13-tetraaza-cyclohexadecane with Cobalt(II), Nickel(II), Copper(II) and Zinc(II); Structural and Molecular Mechanics Studies

2000 ◽  
Vol 53 (9) ◽  
pp. 727 ◽  
Author(s):  
Neil F. Curtis ◽  
Olga P. Gladkikh
Keyword(s):  
Molecular Mechanics ◽  
Ground State ◽  
Boat Conformation ◽  
Singlet Ground State ◽  
X Ray Diffraction ◽  
Molecular Plane ◽  
X Ray ◽  
Counter Ions ◽  
Twist Boat ◽  
Chelate Rings

The cyclic tetraamine compound (4RS,12RS)-(2,2,4,10,10,12-hexamethyl-1,5,9,13-tetraazacyclohexadecane) nickel(II) perchlorate, [Ni(L1 )] (ClO4)2, has been prepared by reduction of the imine functions of (2,4,4,10,12,12-hexamethyl-1,5,9,13-tetraazacyclohexadeca-1,9-diene)nickel(II) by catalytic hydrogenation, or by NaBH4 in acetonitrile/methanol. The ligand L 1 was isolated, after reaction with acid, as the salt [(L 1 )H4](ClO4)Cl3·H2O. Compounds with cobalt(II), copper(II), and zinc(II) were prepared from this, and the structures of [M(L 1 )] (ClO4)2, M = Co, Ni and Cu, and [Cu(L 1 )] [ZnCl4], determined by X-ray diffraction: [Co(C18H40N4)] (ClO4)2, orthorhombic, Pn21/a, a 8.644(3), b 14.869(8), c 19.541(7) Å, Z 4, R1 0.062 for 99 reflections with I > 2s(I); [Ni(C18H40N4)] (ClO4)2, monoclinic, C2/c, a 11.780(4), b 12.580(4), c 16.930(3) Å, b 90.14(4)˚, Z 4, R1 0.067 for 1644 reflections with I > 2s(I); [Cu(C18H40N4)] (ClO4)2, monoclinic, C2/c, a 11.508(7), b 13.17(2), c 16.83(1) Å, b 92.37(5)˚, Z 4, R1 0.114 for 2366 reflections with I > 2s(I); [Cu(C18H40N4)] [ZnCl4], monoclinic, P21/n, a 9.392(3), b 14.915(6), c 17.591(7) Å, b 95.94(3)˚, Z 4, R1 0.041 for 2301 reflections with I > 2s(I). All have the C-rac, 1RS,4SR,5RS,9RS,12RS,13SR, configuration with N–H groups alternating on opposite sides of the molecular ‘plane’ around the ring. All have flattened tetrahedral coordination geometry, with the quartet ground state cobalt(II) cation most twisted and the copper(II) tetrachlorozincate, perchlorate and singlet ground state nickel(II) complex cations progressively more flattened. The macrocycles have overall saddle-like conformations with chelate rings tilted alternately to opposite sides of the molecular ‘plane’. The compounds all have both trimethyl-substituted chelate rings in chair conformations. The unsubstituted chelate rings both have chair conformations for the cobalt(II) compound, both have twist-boat conformations for the nickel(II) and copper(II) perchlorate salts and have one chair and one twist-boat conformation for the copper(II) tetrachlorozincate salt. Mean M–N distances (Å) and trans-N–M–N angles {N(1)–M–N(9), N(5)–M–N(13) (degrees)} are: Co, 1.99, 130.3(5), 115.5(5); Ni, 1.93, 163.6(4), 155.8(4); Cu (ClO4), 1.99, 155.0(6), 143.8(7); Cu (ZnCl4) 2.00, 146.6(2), 135.0(2). The influence of axial interactions with counter ions, hydrogen bonding and other lattice interactions on the structures adopted are discussed. Strain energies for the possible configurations/conformations of coordinated L 1 have been calculated by molecular mechanics and related to the observed structures.

Preparation, and complexes with nickel(II) and copper(II), of a diazepane amine alcohol. The structure of [4,4-dimethyl-7-(5,5,7-trimethyl-1,4-diazepan-1-yl)-5-azaheptan-2-ol]nickel(II) perchlorate

1983 ◽  
Vol 36 (7) ◽  
pp. 1341 ◽  
Author(s):  
KR Morgan ◽  
GJ Gainsford ◽  
NF Curtis
Keyword(s):  
Ground State ◽  
Coordination Compounds ◽  
Major Product ◽  
Boat Conformation ◽  
Singlet Ground State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Donor ◽  
Square Planar ◽  
Coordination Plane

Reduction of 4,4,12,12-tetramethyl-5,8,11-triazapentadecane-2,14-dione diperchlorate by sodium borohydride yields as the major product one isomer of 4,4-dimethyl-7-(5,5,7-trimethyl-1,2-diazepam 1-yl)-5-azaheptan-2-ol, pyaz. The coordination compounds [M(pyaz)] (ClO4), and [Ni(pyaz)(NCS)] CNS (M = NiII, CuII) were prepared, the latter being assigned five-coordinate structures. The structure of singlet ground state [Ni(pyaz)] (ClO4)2 was determined by X-ray diffraction [space group P212121, Z 4, a 1450.8(2), b 1522.2(1), c 1048.5(1) pm, R 0.0675, Rw 0.0768 for 2461 reflections]. The compound has a square-planar coordination arrangement, with the three nitrogen and the oxygen donor atoms of the pyaz ligand approximately coplanar [Ni-O 190.0(6) pm; Ni-N 192.8(6), 189.2(6), 189.2(6) pm in sequence N(5) of chain, N(l), N(4) of diazepane]. The diazepane ring adopts a boat conformation. One side of the nickel(II) coordination plane is sterically crowded by the presence of two axial methyl substituents. The ligand has two non-equivalent chiral centres (C(14) of the diazepane ring and C(2) of the amine alcohol chain), both present in the R configuration in the crystal studied. The three nitrogen atoms, which became chiral centres upon coordination, are present in the S configuration for two diazepane nitrogen atoms and in the R configuration for the 5-aza chain nitrogen.

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.

Synthesis and characterization of 2,2-diphenyl-1-(5-acetonyl-2,4,6-trinitro-1,3-cyclohexadienyl)hydrazine, C21H19N5O7

1993 ◽  
Vol 71 (7) ◽  
pp. 1057-1063 ◽  
Author(s):  
Donna L. Draper ◽  
Richard J. Barton ◽  
Beverly E. Robertson ◽  
Barbara R. Nelson ◽  
John A. Weil
Keyword(s):  
Nitro Group ◽  
Synthesis And Characterization ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Phenyl Rings ◽  
Common Plane ◽  
Twist Boat

The reaction of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazine with the enolate of acetone, followed by acidification, yields the title compound 2,2-diphenyl-1-(5-acetonyl-2,4,6-trinitro-1,3-cyclohexadienyl)hydrazine, C21H19N5O7. The identity of the latter was confirmed by a combination of mass spectrometry, FTIR, elemental analysis, and 1H NMR. Crystals were grown from dichloromethane –95% ethanol and the structure was determined by X-ray diffraction. Crystals are monoclinic, P21/c, a = 9.254(3), b = 13.531(3), c = 17.39(5) Å, β = 106.18(2)° at 225 K. R = 0.073, Rω = 0.038 for reflections with I > 2σ(I). The Zachariasen extinction factor, g, refined to 18(3) × 10−4. The cyclohexadiene ring is puckered with a primarily twist-boat conformation. Atoms C(1) to C(3), C(6), the nitro group on C(2), and the hydrazine moiety (N(8)—N(7)—H(7) attached to C(1)) all lie close to a common plane. The planes of the two phenyl rings, the acetonyl substituent, and the C(6) nitro group are each roughly perpendicular to this plane. The C(5) acetonyl and C(6) nitro groups are trans to each other.

scholarly journals Spectral Analysis and Crystal Structures of 4-(4-Methylphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole and 4-(4-Methoxyphenyl)-6-Phenyl-2,3,3a, 4-Tetrahydro-1H-Pyrido[3,2,1-jk]Carbazole

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
J. Kalyana Sundar ◽  
S. Natarajan ◽  
S. Chitra ◽  
Nidhin Paul ◽  
P. Manisankar ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Spectroscopic Properties ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Triclinic System ◽  
New Compounds ◽  
Twist Boat

The crystal structures of 4-(4-methylphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIa) and 4-(4-methoxyphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIb) were elucidated by single crystal X-ray diffraction. Compound (IIa), C28H25N, crystallizes in the triclinic system, space group P-1, with a=8.936(2) Å,b=10.490(1) Å,c=11.801(1) Å,α=102.69(5)°, β=103.27(3)°,γ=93.80(1)°, and Z=2. The compound (IIb), C28H25NO, crystallizes in the monoclinic system, space group P21/a, with a=11.376(5) Å,b=14.139(3) Å,c=13.237(4) Å,β=97.41(3)°, and Z=4. In both the structures, the pyrido ring adopts a twist boat conformation and the carbazole molecule has the twisted envelope structure with C3 and C13 at the flap. No classical hydrogen bonds are observed in the crystal structures. Details of the preparation, structures, and spectroscopic properties of the new compounds are discussed.

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.

Reactions of (η5-C9H7)Rh(η2-C2H4)2 with quinones: molecular structure of [(η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4)]

1999 ◽  
Vol 77 (2) ◽  
pp. 199-204
Author(s):  
Stephen A Westcott ◽  
Nicholas J Taylor ◽  
Todd B Marder
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Ground State ◽  
Slip Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Hinge Angle

Reactions of (η5-C9H7)Rh(η2-C2H4)2 (1) with quinones were investigated. Substitution of the labile ethylene ligands was observed upon addition of either duroquinone (2,3,5,6-tetramethyl-1,4-benzoquinone) or 1,4-benzoquinone to complex 1. The molecular structure of neutral (η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4) (3), determined by X-ray diffraction, shows that the duroquinone ligand lies in a plane nearly parallel to the indenyl group. The carbonyl moieties of duroquinone lie in a plane incorporating Rh, C2, and the midpoint between C3a and C7a of the indenyl ring. The slip parameter (Δ= d(average Rh-C3a,7a) -d(average Rh-C1,3)) was calculated to be 0.112(2) Å; whereas a value of ca. 0.05 Å had been obtained previously from film data. Values for the hinge angle (HA = angle between normals to the least-squares planes defined by C1, C2, C3 and C1, C7a, C3a, C3) and fold angle (FA = angle between normals to the least-squares planes defined by C1, C2, C3 and C3a, C4, C5, C7, C7a) are 7.2° and 4.0°, respectively.Key words: indenyl, rhodium, quinones, ring-slippage, ground-state distortion.

Comparative Spectroscopic Studies on Luminescence Performance of Er3+ Doped Tellurite Glass Embedded with Different Nanoparticles (Ag Co and Fe) at 0.55 μm Emission

2021 ◽  
Vol 317 ◽  
pp. 81-86
Author(s):  
Syariffah Nurathirah Syed Yaacob ◽  
Md. Rahim Sahar ◽  
Faizani Mohd Noor ◽  
Nur Liyana Amiar Rodin ◽  
Siti Khadijah Mohd Zain ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Ground State ◽  
Tellurite Glass ◽  
Spectroscopic Studies ◽  
The Other ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Doped Glass ◽  
Luminescence Performance

The spectroscopic performance of Er3+ doped glass at 0.55 mm emission contain different nanoparticles NPs have been comparatively evaluated. Glass containing 1.0 mol % of Er3+ doped with different NPs (Ag, Co and Fe ) have been prepared using melt quenching technique. X-ray diffraction analysis reveals the all the prepared samples are amorphous. The UV-Vis absorption spectra of all glasses show several prominent peaks at 525 nm, 660 nm, 801nm, 982 nm and 959 nm due to transition from ground state 4I15/2 to different excited of 2H11/2, 4F9/2, 4I9/2, 4I11/2, and 4I13/2. The emission of Er3+ at 0.55 mm for glass contain Ag NP shows significant enhancement about 3 folds up to 0.6 mol%. On the other hand, the emission of Er3+ at 0.55 mm for glass containing Fe NPs and Co NPs intensely quench probably due to the energy-transfer from Er3+ ion to NPs and magnetic contributions.

scholarly journals Unusual formation of (E)-11-(aminomethylene)-8,9,10,11-tetrahydropyrido[2′,3′:4,5]pyrimido[1,2-a]azepin-5(7H)-one and its crystal structure

2017 ◽  
Vol 73 (10) ◽  
pp. 1497-1500
Author(s):  
Khamid U. Khodjaniyazov ◽  
Utkir S. Makhmudov ◽  
Kambarali K. Turgunov ◽  
Burkhon Z. Elmuradov
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Aqueous Ammonia ◽  
Boat Conformation ◽  
X Ray ◽  
First Time ◽  
Twist Boat ◽  
Unusual Formation

Selective C-formylation of 8,9,10,11-tetrahydropyrido[2′,3′:4,5]pyrimido[1,2-a]-azepin-5(7H)-one has been studied for the first time. It was revealed that formylation proceeds by the formation of an intermediate salt, which due to the re-amination process on treatment with aqueous ammonia transformed into the corresponding (E)-11-(aminomethylene)-8,9,10,11-tetrahydropyrido[2′,3′:4,5]-pyrimido[1,2-a]azepin-5(7H)-one, C13H14N4O, as anE-isomer. Formylation was carried out by Vilsmeier–Haack reagent and the structure of the synthesized compound was confirmed by X-ray structural analysis, spectroscopic and LC–MS methods. In the molecule, the seven-membered pentamethylene ring adopts a twist-boat conformation.

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.

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