Synthesis and crystal structure of a macrocyclic azidotetraamine copper(II) complex

The complex [Cu(L)N₃](H₂O)(ClO₄) (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18, 0^7.12]docosane) has been prepared and characterized by X-ray crystallography. 1 crystallizes in the monoclinic space group P2₁/c, with a = 8.907(5), b = 20.036(3), c = 14.773(2) Å, = 103.78(2)°, V = 2560.6(15) ų, and Z = 4. The coordination geometry around the Cu(II) ion is a distorted square-pyramidal with four nitrogen atoms of the macrocycle and one nitrogen atom of the axial azido group.     

Synthesis and characterization of copper(II) tetraaza macrocyclic complex with 2- benzimidazolepropionate ligand

A mononuclear complex [Cu(L)(bip)₂] (1) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo [14,4,0^1.18, 0^7.12]docosane; bip = 2-benzimidazolepropionate) has been synthesized and structurally characterized by X-ray crystal structure analysis. The crystals are monoclinic P2 ₁/n with a = 10.2990(2), b = 15.9400(3), c = 11.991(14) Å, = 101.92(7)°, V = 1926(2) ų, Z = 2. The copper(II) coordination geometry exhibits an axially elongated octahedron with four nitrogen atoms from the macrocycle and two oxygen atoms from the bip ligands. The cyclic voltammogram of 1gives 2 one-electron waves corresponding to Cu^II/Cu^III and Cu^II/Cu^I processes.     

Synthesis, spectroscopy, and X-ray structures of fac-(CO)3(dppe)MnSC(S)H, fac-(CO)3(dppe)ReSC(S)H, fac-(CO)3(dppp)ReSC(S)H, and fac-(CO)3(dppb)ReSC(S)H

The monodentate dithioformato complexes, fac-(CO)₃(dppe)MnSC(S)H (1), fac- (CO)₃(dppe)ReSC(S)H (2), fac-(CO)₃(dppp)ReSC(S)H (3), and fac-(CO)₃ (dppb)ReSC(S)H (4), where dppe is 1,2-bis(diphenylphosphino)ethane, dppp is 1,3-bis(diphenylphosphino)propane, and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized from the treatment of the corresponding hydrides, fac-(CO)₃ (P-P)MSC(S)H with CS₂. Compounds 1–4 crystallize in the monoclinic crystal system: for 1, space group = P2₁/c, a = 15.3139(3) Å, b = 9.7297(4) Å, c = 19.0991(6) Å, = 105.928(1), V = 2736.5 ų, Z = 4; for 2, space group = P2₁/c, a = 15.6395(8) Å, b = 9.8182(5) Å, c = 19.4153(11) Å, = 106.741(1), V = 2854.9(3) ų, Z = 4; for 3, space group = P2₁/n, a = 11.3570(10) Å, b = 19.465(2) Å, c = 15.5702(14) Å, = 104.776(2), V = 3328.3(5) ų, Z = 4; and for 4, space group = C2/c, a = 32.078(2) Å, b = 10.4741(6) Å, c = 19.0608(9) Å, = 94.315(2), V = 6386.1(6) ų, Z = 8.     

Synthesis, crystal structures, and properties of copper complexes with tripodal ligands and azide anion

Two new Cu^II complexes, (CuL¹N₃)ClO₄ (1) and (CuL²N₃)ClO₄ (2), have been synthesized and characterized in the presence of NaN₃, where L¹ = tris[2-(6-methylpyridyl)methyl]amine and L² = tris[(3,5-dimethylpyrazol-l-yl)methyl]amine, and their crystal structures have been determined by X-ray diffraction methods. Compound 1 crystallizes in the triclinic space group P–1, with a = 8.258(2) Å, b = 11.481(2) Å, c = 14.158(3) Å, = 72.30(3)°, = 79.05(3)°, = 86.08(3)°, V = 1255.4(5) ų. Compound 2 crystallizes in the monoclinic space group C2/c, with a = 26.752(2) Å, b = 10.561(2) Å, c = 21.059(4) Å, = 120.51(3)°, V = 5126(3) ų. In both compounds, each Cu^II center is in a distorted trigonal–bipyramidal coordinated environment with four nitrogen atoms from the tripodal ligand and one nitrogen atom from the azide group. The coordination geometry around Cu^II center of 1 is axially compressed trigonal bipyramid, while that of 2 is an axially elongated trigonal bipyramid. The coordinated azide group is in the axial site in both complexes. A quasi-dimeric structure of 1 has been formed in the unit cell through hydrogen bonding. The electronic spectra of two complexes in solution have been further studied by UV–vis technique, and the coordination properties have been discussed.     

Regiospecific ligand addition to the donor–acceptor compound Ru2(CO)6(bpcd): syntheses and X-ray diffraction structures of Ru2(CO)5L(bpcd) and Ru2(CO)5L[μ-C=C(PPh2)C(O)CH2C}(O)](μ2-PPh2) (where L = PMe3 and tBuNC)

Thermal and Me₃NO-assisted activation of the donor–acceptor complex Ru₂(CO)₆(bpcd) (1) [where bpcd = 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione] with PMe₃ or ^tBuNC affords the mono-substituted complexes Ru₂(CO)₅L(bpcd), as a result of regiospecific ligand attack at the diphosphine-substituted ruthenium center. Solution NMR measurements (¹H and ³¹P) reveal that the PMe₃ derivative exists as a noninterconverting mixture of axial (3a) and equatorial (3e) isomers, with the only the equatorial isomer being observed for Ru₂(CO)₅(^tBuNC)(bpcd) (5). Near-UV irradiation of 1 in the presence of added ligand yields Ru₂(CO)₅L(bpcd), in addition to the known ₂-phosphido complex Ru²(CO)⁶ [-C=C(PPh₂)C(O)CH₂C(O)](₂-PPh₂) (2) and the corresponding phosphido-substituted complexes Ru²(CO)_5L[-{C =C(PPh₂)C(O)CH₂C}(O)]₂-PPh₂)[4 (L = PMe₃); 6 (L = ^tBuNC)]. As with compounds 3a, 3e, and 5, both 4 and 6 exhibit ligand attachment at the diphosphine-substituted ruthenium center. The molecular structures of 3e, 4, 5, and 6 were determined by X-ray crystallography. 3e, as the 1/2 C₆H₆ solvate, crystallizes in the monoclinic space group C2/c: a = 40.573(3) Å, b = 10.2663(9) Å, c = 18.347(1) Å, = 95.371(6)°, V = 7609(1) ų and Z = 8; 4, crystallizes in the monoclinic space group P2₁/n: a = 10.8241(8) Å, b = 18.074(1) Å, c = 19.194(1) Å, = 96.968(6)°, V = 3727.3(5) ų, and Z = 4; 5, as the 1/2CH₂Cl₂ solvate, crystallizes in the monoclinic space group C2/c: a = 40.955(3) Å, b = 9.7230(6) Å, c = 20.542(1) Å, = 106.596(5)°, V = 7839.2(9) ų, and Z = 8; 6, as the 1/2C₅H₁₂ solvate, crystallizes in the monoclinic space group P2₁/c: a = 21.773(2) Å, b = 10.907(3) Å, c = 18.744(4) Å, = 114.68(1)°, V = 4045(1) ų, and Z = 4. The site occupied by the PMe₃ and ^tBuNC ligands in these compounds is discussed relative to the steric size/electronic properties of the ancillary ligand and its interaction with the bpcd ligand.     

A novel four-coordinate zinc(II) complex of the di-N-hydroxypropylated tetraaza macrocycle

The compound [Zn(L²)Cl]ClO₄·H₂O (1) (L² = 2,13,-bis(3-hydroxypropyl)-5,16-di-methyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) has been synthesized and structurally characterized. 1 crystallizes in the monoclinic system, space group P2₁/c with a = 8.932(2), b = 16.189(2), c = 22.492(4) Å = 95.34(2)° V = 3238.3(11) ų; and Z = 4. The zinc atom is placed in a highly distorted tetrahedral environment bonding with three nitrogen atoms of the macrocycle and one chlorine atom.     

Crystal structure of a salt of the pyridinium-pyridine ion by X-ray and neutron diffraction

The crystal structure of [(C₅H₅N)₂H]⁺[ZnBr_3/2Cl_3/2(C₅H₅N)]^– has been determined and refined by full-matrix least-squares methods using X-ray (R, on ¦F _o¦, = 0.045 with 2291 reflections) and neutron (¯R, on ¦F _o¦, = 0.035 with 2030 reflections) diffraction data. The crystals of the compound are monoclinic, space groupP2₁/c witha = 12.728(1),b = 11.600(1),c = 13.354(1) Å, = 107.38(1) °,Z = 4,D _x = 1.68, andD _m(flotation) = 1.69 g cm^–3. The X-ray and neutron intensities were measured by the counter -2 scan technique with CuK X-rays ( = 1.5418 Å) and neutrons with = 1.109 Å, respectively. An intramolecular N--H hydrogen bond holds pairs of pyridine molecules together in the lattice [N N, 2.737(3) Å]. The hydrogen atom is very asymmetrically disposed with N-H distances of 1.086(7) Å and 1.658(6) Å. The coordination about the zinc atom is tetrahedral with the nitrogen atom of the pyridine molecule in one tetrahedral position and different mixtures of the two halogen atoms in the other three positions. The important average bond distances from the neutron study are Zn-N [2.073(3) Å], Zn-Cl [2.251(2) Å], Zn-Br [2.394(3) Å], N-C [1.334(5) Å], C-C [1.378(5) Å], and C-H [1.075(7) Å].     

Two-dimensional nickel(II) tetraaza macrocyclic complex linked by hydrogen bonds

The complex [Ni(L)](PDC) 2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[16,4, 0^1.18,0^7.12]docosane; PDC = 3,5-pyrazoledicarboxylate) has been synthesized and characterized by X-ray crystallography. It crystallizes in the monoclinic system P2₁/c with a = 9.739(4) Å, b = 10.491(3) Å, c = 16.884(3) Å, = 97.17(2)°, V = 1711.5(8) ų, Z = 4. The coordination environment around the nickel(II) ion exhibits a slightly distorted square-plane with four secondary amines of the macrocycle. The title compound is interconnected to give a two-dimensional network through the hydrogen-bonding interactions.     

Synthesis and crystal structure of bis(2,2′-bipyridyl)mononitritozinc(II) perchlorate. An example of a six-coordinate cis-octahedral ZnN4O2 chromophore

The crystal structure of bis(2,2-bipyridyl)mononitritozinc(II) perchlorate, [Zn(bipy)₂ (ONO)][ClO₄] (1) has been determined. The complex is monoclinic, with a = 10.9195(4) Å, b = 12.2320(5) Å, c = 16.5477(8) Å, = 105.6150(10), P2₁/n space group, with final R1 = 0.0657 and wR2 = 0.1630. The complex involves a [Zn(bipy)₂ (ONO)]⁺ cation and a [ClO₄]^– anion. The ZnN₄O₂ chromophore is six-coordinate, with a cis-distortion of the two oxygens of the nitrite, O(1) and O(2), at distances 2.216(5) and 2.197(5) Å from the zinc (Zn– O _mean = 2.206(5) Å, O = 0.019(5) Å) and two out of plane Zn–N bonds, Zn–N(2) and Zn–N(3), at 2.129(4) and 2.135(4) Å (Zn–n _mean/out = 2.132(4) Å, n _2,3 = 0.006(4) Å). The two inplane nitrogens, N(1) and N(4), at distances Zn–N(1) = 2.090(4) and Zn–N(4) = 2.085(4) Å (Zn–n _mean/in = 2.087(4) Å, n _1,4 = 0.005(4) Å) are greater than 2.0 Å, but slightly shorter than the axial bonds. The inplane angles ₁, ₂, and ₃ in 1 have values 150.33(18), 108.98(17), and 99.73(18) respectively. The stereochemistry is cis-distorted octahedral, with an ₃ = 99.37(18), which is lower than ₃ = 103.4(1) observed in [Zn(bipy)₂(ONO)][NO₃] (5). Comparison with the corresponding [Cu(bipy)₂(ONO)][Y] complexes suggested that the cis-distortion of the CuN₄O₂ chromophore in the copper(II) series does not originate in the Jahn–Teller or pseudo-Jahn–Teller effect.     

Synthesis of homoleptic lanthanide amides and the crystal structure of [Li(THF)4][Y(NPh2)4]

Anhydrous LnCl₃ reacted with three equivalents of LiNPh₂ in THF to give the unexpected homoleptic lanthanide amides [Li(THF)₄][Ln(NPh₂)₄] (Ln = Sm (1), Y (2)) in high yield. The crystal structure of complex 2 has been determined by X-ray diffraction methods. It crystallizes in the orthorhombic space group Pbcn with a = 17.522(3) Å, b = 16.321(3) Å, c = 19.947(3) Å, V = 5704.4(17) ų, and D _calc = 1.231 mg/m³ for Z = 4. Complex 2 is composed of discrete [Li(THF)₄]⁺ cations and [Y(NPh₂)₄]^– anions, both of which have crystallographically imposed two-fold symmetry. To achieve steric saturation of the metal center, there are interactions between the yttrium atom and one -carbon atom of each amide ligand. The yttrium and lithium atoms both exhibit distorted tetrahedral coordination geometry.     

Crystal and molecular structure of 1-phenyl-3-(2-hydroxyphenylamino)-2-buten-1-one,C16H15NO2

Orange, yellow, and colorless crystals were obtained for the title compound. The orange crystals are triclinic, space groupP¯1,a=9.181(2),b=10.734(2),c=15.245(3) Å,=73.06(2),=79.21(2), =67.83(2)°,V=1325.9(5) ų,Z=4. Two different symmetry-independent molecules (moleculeA andB) were determined in the crystal unit. The conformation ofA is stabilized by an intramolecular H bond from the amino NH to the keto and phenolic O atoms [1.89(2) and 2.38(2) Å, respectively]. The conformation ofB is stabilized by only one intramolecular H bond, from the amino NH to the keto O atom [1.925(2) Å]. The colorless crystals (moleculeC) are monoclinic, space groupP2₁/n,a=11.883(3),b=11.004(3),c=10.053(3) Å,=95.93(3)°,V=1307.5(6) ų,Z=4. This conformation is stabilized by one intramolecular H bond, the same as in B, with N-HO, 1.84(3) Å. An intermolecular H bond is observed forA,B, and C, O-HO, 2.634(2), 2.640(2), and 2.697(2) Å, respectively. The yellow crystals are adducts with ethanol (¹H NMR, infrared and GC measurements).     

Structural studies of N(4)-substituted thiosemicarbazones prepared from 4-formylantipyrine and a thiourea derived from 4-aminoantipyrine

Reaction of 4-formylantipyrine with N(4)-dimethylthiosemicarbazide and 3-piperidylthiosemicarbazide produces the N(4)-dimethylthiosemicarbazone (1), and the 3-piperidyl-thiosemicarbazone (2), respectively. Compound 1 is triclinic, space group P-1 with a = 6.329(1) Å, b = 11.699(1) Å, c = 11.943(1) Å, = 65.83(1)°, = 80.83(1)°, = 84.90(1)°, and V = 796.1(1) ų with Z = 2, for D _calc = 1.324 g/cm³. Compound 2 is triclinic, space group P-1 with a = 6.784(1) Å, b = 10.485(2) Å, c = 13.462(3) Å, = 102.05(2)°, = 98.61(2)°, = 101.32(2)°, and V = 899.8(5) ų with Z = 2, for D _calc = 1.319 g/cm³. Reaction of 4-aminoantipyrine with phenyl isothiocyanate produced N-antipyrine-N-phenylthiourea (3). Compound 3 is monoclinic, space group P2₁/n with a = 6.863(7) Å, b = 15.361(3) Å, c = 16.332(5) Å, = 90.35(6)°, and V = 1720.7(18) ų with Z = 4, for D _calc = 1.306 g/cm³. Compounds 1 and 2 have intermolecular hydrogen bonding between the carbonyl oxygen of the antipyrine moiety and the NH hydrogen of the thiosemicarbazone moiety. In 3 the two unique molecules are held together as a dimer by interactions of the two thiourea NH's and the antipyrine moiety's\break oxygen.     

Preparation and characterization of 1-butyl-3-methylimidazolium tetrakis(3,5-bis(trifluoromethyl) phenyl)borate, [bmim]BARF

Attempts to prepare novel air and moisture stable room-temperature ionic liquids have afforded a new 1,3-dialkylimidazolium tetraarylborate salt: 1-butyl-3-methylimidazolium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, [bmim]BARF, 1. Crystal data: C₈₀ H ₅₄ b ₂F₄₈N₄, monoclinic space group P2(1)/n, a = 21.2622(17) Å, b = 15.8037(13) Å, c = 26.227(2) Å, = 101.841(2) , V = 8625.3(12) ų, Z = 1.544.     

Study of the sulfur atom as hydrogen bond acceptor in N(2)-pyridylmethyl-N′-arylthioureas

The hydrogen acceptor capability of the sulfur atom in the biologically relevant N-2-pyridylmethyl-N-arilthioureas was explored. N-2-Pyridylmethyl thioreas were selected to avoid the formation of intramolecular six-membered hydrogen-bonded ring. The compounds studied were N-2-pyridylmethyl-N-phenylthiourea (1), N-2-pyridylmethyl-N-2-methoxythiourea (2), N-2-pyridylmethyl-N-4-methoxyphenylthiourea (3), and N-2-pyridylmethyl-N-4-bromophenylthiourea (4). 1 crystallizes in the monoclinic space group P2₁/c, with a = 7.419(1) Å, b = 18.437(2) Å, c = 9.656(1) Å, = 106.277(6)°, V = 1267.8(3) ų, Z = 4. 2 crystallizes in the monoclinic space group P2₁/c, with a = 8.064(2) Å, b = 18.382(7) Å, c = 9.865(5) Å, = 97.81(3)°, V = 1448.8(11) ų, Z = 4. 3 crystallizes in the monoclinic space group P2₁/c, with a = 11.472(1) Å, b = 13.520(1) Å, c = 10.088(1) Å, = 112.60(1)°, V = 1444.5(2) ų, Z = 4. 4 crystallizes in the triclinic space group P-1, with a = 4.583(3) Å, b = 10.263(3) Å, c = 14.396(3) Å, = 77.92(2)°, = 88.55(4)°, = 80.02(4)°, V = 652.1(5) ų, Z = 2. Both thiourea N–H groups form intermolecular hydrogen bonds, one with the thione sulfur atom and the other with the pyridine nitrogen atom but the H-bonding schemes are not the same maybe due to the flexibility of the molecules.     

Keto–enol tautomerism, conformations, and structure of 1-[N-(4-chlorophenyl)]aminomethylidene-2(1H)naphthalenone

1-[N-(4-chlorophenyl)]aminomethylidene-2(1H)naphthalenone (C₁₇H₁₂NOCl) (1) was synthesized and the crystal structure was determined. Compound 1 crystallizes in the monoclinic space group P2₁/n with a = 4.761(3) Å, b = 20.347(1) Å, c = 13.773(2) Å, = 92.89(3)°, V = 1332.4(3) ų, Z = 4, D _c = 1.404 g cm^–3, (Mo K) = 0.28 mm^–1, and R = 0.036 for 2680 reflections [I > 2(I)]. Molecule 1 is not planar, and the dihedral angle between the naphthaldeyde plane A [C1–C11, 01] and the 4-chloroaniline plane B [C12–C17, C11, N1] is 20.1(3)°. An intramolecular hydrogen bond occurs between the hydroxyl oxygen and imine nitrogen atoms [2.528(3) Å]. IR, ¹H NMR, and UV measurements and AM1 semiempirical quantum mechanical calculations support the keto form found in the X-ray structure.     

Synthesis, crystal structure and properties of square-planar acetato{[(4-methylimidazol-5-yl)methylene]histamine} copper(II) perchlorate

The square-planar complex [Cu(MIMH)(CH₃CO₂)](ClO₄) (1) (MIMH = [(4-methylimidazol-5-yl)methylene]histamine) was prepared and structurally characterized. Complex 1 crystallizes in the monoclinic space group P2₁/n with a = 10.5331(10), b = 12.6177(10), c = 12.9773(10) Å, = 107.710(10)°, V = 1643.0(2) ų, and Z = 4. Single-crystal X-ray analysis reveals that the copper(II) atom in 1 has a distorted square-planar environment defined by three nitrogen atoms from the Schiff base ligand and one oxygen atom from the acetate group. The Cu—N bond lengths range from 1.950(3) to 2.015(3) Å and the Cu—O(1) bond length is 1.952(2) Å. The electronic spectra of 1 in aqueous solutions indicates that 1 forms adducts of square-pyramidal geometry with H₂O. Cyclic voltammetry of 1 in DMF solution shows that there is some degradation of 1 upon reduction.     

A cobalt(II) complex with the N,N,O-tridentate ligand 6-amino-5-formyl-1,3-dimethyluracilato-benzoyl-hydrazone

The crystal structure of bis-(6-amino-5-formyl-1,3-dimethyluracilato benzoylhydrazone)cobalt(II) dimethylformamide solvate is described. This compound crystallizes in the triclinic system, space group P1¯, Z = 2 with a = 9.7368(8), b = 12.346(1), c = 17.184(1) Å, = 78.372(6), = 74.585(6), = 71.113(5)°, and V = 1869.0(3) ų. The coordination polyhedron around the metal ion displays a slightly flattened M(NNO)₂ octahedral shape. Both ligands bind in a trident fashion through the benzoylic oxygen atom, the hydrazone nitrogen atom closer to the uracil ring, and the deprotonated nitrogen atom of the amino group. The two ligands exhibit quite different conformations: one of them is almost planar, whereas the other is severely twisted.     

Synthesis and characterization of copper(II) hexaazamacrotetracyclic complex with thiocynate ligand

A mononuclear complex [Cu(L)(NCS)](ClO₄) (1) (L = 1,3,10,12,16,19-hexaazatetracyclo [17,3,1, 1^12.16,0^4.9]tetracosane) has been synthesized and structurally characterized by X-ray crystal structure analysis. The crystals are monoclinic P2₁2₁2₁ with a = 9.596(1), b = 11.285(1), c = 22.446(2) Å, V = 2430.7(3) ų, Z = 4. The copper atom is coordinated by two secondary and two tertiary amines of the macrocycle and one nitrogen atom of the thiocynate ligand in a distorted square-pyramidal geometry. The cyclic voltammogram of 1 exhibits two waves of a one-electron transfer corresponding to Cu^II/Cu^III and Cu^II/Cu^I processes.     

Intramolecular hydrogen bonding and tautomerism in 1-[N-(4-bromophenyl)]aminomethylidene-2(1H) naphthalenone

1-[N-(4-bromophenyl)]aminomethylidene-2(1H)naphthalenone (C₁₇H₁₂NOBr) (1) was synthesized and its crystal structure was determined. Compound (1) is monoclinic, space group P2₁/n with a = 4.808(1) Å, b = 20.617(1) Å, c = 13.750(1) Å, = 93.004(1)°, V = 1361.11(3) ų, Z = 4, D_c = 1.592 g·cm^–3, (Mo K) = 3.014 mm^–1, R = 0.051 for 1013 reflections [I > 2(I)]. There is a strong intramolecular hydrogen bond of distance 2.544(2) Å between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the nitrogen atom. The title molecule is not planar. X-ray crystal structure determination reveals the existence of the keto (or predominantly keto) tautomer in (1). Spectra of compound (1) were observed by IR and NMR, and UV–visible spectra of (1) were studied in different solvents and acidic media.     

Short H· · ·H distances in norbornene derivatives

A short H···H intramolecular interaction was reported previously for an anhydride of syn-sesquinorbornene. The synthesis and structure of a such an anhydride with an additional five-membered dithiole ring has been investigated. While hydrogen atom positions are not accurately located, the 1.62 Å separation indicates this molecule is a candidate for the shortest H···H interaction. Two cycloadducts of norbornadiene, which literature suggests might exhibit additional short interactions, are reported also; however, the isomers with minimal intramolecular interactions are the isolated products. C₂₂H₂₀O₃S₂, 3, crystallizes in P with a = 10.881(4), b = 13.712(8), C = 6.548(8) Å, = 101.32(6), = 107.49(5), = 90.49(4)°, D _calc = 1.445 g cm^–3, and Z = 2, C₂₁H₂₀O₄Cl₈, 5, in P2₁/n with a = 8.168(2), b = 13.488(4), c = 23.500(6) Å, = 94.72(2)°, D _calc = 1.597 g cm^–3, and Z = 4, C₂₁H₂₈O₄, 6, in P> with a = 12.667(2), b = 12.792(2), c = 12.540(2) Å, = 113.51(1), = 98.18(1), = 74.39(1)°, D _calc = 1.276 g cm^–3, and Z = 4.