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The crystal structure of the phthaloyl-linked benzotriazole 1,1'-(phthaloyl)­bis­(benzotriazole), C20H12N6O2, having potential as a corrosion inhibitor for copper, confirms that the ortho-related carbox­amide substituents in the benzene parent ring adopt a syn-syn conformation with respect to one another.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801011011/ci6043sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536801011011/ci6043Isup2.hkl
Contains datablock I

CCDC reference: 170893

Key indicators

  • Single-crystal X-ray study
  • T = 295 K
  • Mean [sigma](C-C) = 0.007 Å
  • R factor = 0.037
  • wR factor = 0.138
  • Data-to-parameter ratio = 8.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes

REFLT_03 From the CIF: _diffrn_reflns_theta_max 27.50 From the CIF: _reflns_number_total 2231 Count of symmetry unique reflns 2232 Completeness (_total/calc) 99.96% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 0 Fraction of Friedel pairs measured 0.000 Are heavy atom types Z>Si present no Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF.

Comment top

Benzotriazole (BTAH) has long been used and remains one of the most effective inhibitors of copper corrosion in neutral and alkaline conditions. (Cotton, 1963; Cotton & Scholes, 1967; Poling, 1970; Mansfeld et al., 1971). Since the mechanism of its inhibition effect is largely attributed to the formation of a polymeric BTA-Cu-BTA-Cu film (Rubim et al., 1993; Ashour et al., 1995), the BTAH derivatives, therefore, may offer higher inhibition efficiencies than the parent molecule, with the extended molecule giving better interaction with the metal surface. With this goal in mind and in an attempt to further understand the mechanism of corrosion inhibition of the carboxybenzotriazoles, a new dicarboxamide, 1,1'-(phthaloyl)bis(benzotriazole), (I), was synthesized (Reid, 1996) and its structure determined using single-crystal X-ray methods.

The analysis shows (Fig. 1) that the ortho-substituted carboxybenzotriazole side chains adopt a syn-syn conformation to one another [torsion angles: C1–C2–C21–O21 = -127.0 (5)° and C6–C1–C11–O11 = -135.2 (5)°]. These chains are slightly distorted from planarity [torsion angles: C1–C11–N11–N12 = 16.3 (6)° and C2–C21–N21–N22 = -9.5 (6)°]. There are no intramolecular associations between the chains and in addition the packing in the unit cell shows no significant intermolecular interactions.

Experimental top

The title compound was synthesized by the slow addition of 20 ml of a solution of phthaloyl chloride (4.3 ml, 60 mmol) in tetrahydrofuran to 100 ml of a solution containing benzotriazole (7.14 g, 60 mmol) and triethylamine (8.4 ml, 60 mmol) (also in tetrahydrofuran), maintained at 273–278 K. After stirring for ca 12 h, the mixture was poured onto ice and the resulting precipitate washed with water and recrystallized from chloroform from which data-quality crystals were obtained.

Refinement top

The positional and isotropic displacement parameters of the H atoms were fixed in the refinement.

Computing details top

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1999a); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 1999b); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON for Windows (Spek, 1999); software used to prepare material for publication: TEXSAN for Windows.

Figures top
[Figure 1] Fig. 1. The molecular configuration and atom-numbering scheme for (I). are shown as 30% probability ellipsoids.
1,1'-(phalolyl)bis(benzotriazole) top
Crystal data top
C20H12N6O2Dx = 1.450 Mg m3
Mr = 368.36Melting point = 464–466 K
Orthorhombic, P212121Mo Kα radiation, λ = 0.71069 Å
a = 10.744 (5) ÅCell parameters from 25 reflections
b = 22.193 (4) Åθ = 8.4–14.7°
c = 7.079 (5) ŵ = 0.10 mm1
V = 1687.9 (14) Å3T = 295 K
Z = 4Plate, colourless
F(000) = 7600.38 × 0.25 × 0.20 mm
Data collection top
Rigaku AFC-7R
diffractometer
Rint = 0.000
Radiation source: Rigaku rotating anodeθmax = 27.5°, θmin = 2.1°
Graphite monochromatorh = 013
ω–2θ scansk = 028
2231 measured reflectionsl = 09
2231 independent reflections3 standard reflections every 150 reflections
992 reflections with I > 2σ(I)' intensity decay: 0.0%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.037H-atom parameters constrained
wR(F2) = 0.138 w = 1/[σ2(Fo2) + (0.0638P)2 + 0.2455P]
where P = (Fo2 + 2Fc2)/3
S = 0.89(Δ/σ)max < 0.001
2231 reflectionsΔρmax = 0.18 e Å3
254 parametersΔρmin = 0.18 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.014 (2)
Crystal data top
C20H12N6O2V = 1687.9 (14) Å3
Mr = 368.36Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 10.744 (5) ŵ = 0.10 mm1
b = 22.193 (4) ÅT = 295 K
c = 7.079 (5) Å0.38 × 0.25 × 0.20 mm
Data collection top
Rigaku AFC-7R
diffractometer
Rint = 0.000
2231 measured reflections3 standard reflections every 150 reflections
2231 independent reflections intensity decay: 0.0%
992 reflections with I > 2σ(I)'
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.138H-atom parameters constrained
S = 0.89Δρmax = 0.18 e Å3
2231 reflectionsΔρmin = 0.18 e Å3
254 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. The absolute configuration could not be determined because of the composition of the compound and the quantity of data collected. The lower than desirable reflection-to-parameter ratio (8.78) is considered acceptable because of the noncentrosymmetric space group (Acta recommended ratio: 8.0).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O110.9414 (3)0.19130 (14)0.1172 (5)0.0514 (9)
O210.6808 (3)0.20081 (14)0.1940 (5)0.0545 (9)
N111.1388 (3)0.17183 (15)0.0238 (5)0.0382 (9)
N121.2205 (4)0.16543 (19)0.1263 (6)0.0514 (11)
N131.3070 (4)0.12837 (19)0.0815 (6)0.0546 (11)
N210.8174 (3)0.12445 (15)0.2230 (6)0.0419 (9)
N220.9395 (3)0.10449 (16)0.2440 (6)0.0485 (10)
N230.9395 (4)0.04697 (16)0.2481 (6)0.0515 (11)
C11.0017 (4)0.23523 (18)0.1734 (6)0.0402 (11)
C20.8883 (4)0.22956 (18)0.2698 (6)0.0396 (11)
C30.8648 (4)0.2658 (2)0.4268 (7)0.0473 (12)
C40.9521 (5)0.3068 (2)0.4859 (7)0.0538 (13)
C51.0631 (5)0.3131 (2)0.3921 (7)0.0520 (13)
C61.0878 (4)0.27723 (19)0.2374 (7)0.0469 (12)
C111.0212 (4)0.19918 (19)0.0001 (7)0.0404 (11)
C141.2838 (4)0.1079 (2)0.1022 (7)0.0445 (12)
C151.3493 (4)0.0662 (2)0.2089 (7)0.0561 (14)
C161.3064 (5)0.0540 (2)0.3865 (8)0.0586 (14)
C171.2006 (5)0.0832 (2)0.4557 (7)0.0552 (14)
C181.1344 (4)0.1248 (2)0.3524 (7)0.0444 (12)
C191.1771 (4)0.13560 (18)0.1692 (6)0.0372 (11)
C210.7875 (4)0.1867 (2)0.2197 (6)0.0415 (11)
C240.8166 (4)0.02648 (19)0.2318 (7)0.0425 (11)
C250.7708 (5)0.0328 (2)0.2411 (8)0.0559 (14)
C260.6447 (5)0.0393 (2)0.2290 (8)0.0607 (15)
C270.5663 (5)0.0104 (2)0.2119 (8)0.0595 (14)
C280.6098 (4)0.0683 (2)0.2031 (7)0.0498 (12)
C290.7382 (4)0.0754 (2)0.2171 (6)0.0398 (10)
H30.78820.26220.49270.056*
H40.93600.33130.59350.064*
H51.12270.34180.43320.061*
H61.16500.28140.17310.055*
H151.42150.04690.16010.066*
H161.34880.02550.46330.069*
H171.17350.07410.58030.065*
H181.06350.14480.40280.052*
H250.82490.06650.25470.067*
H260.60900.07850.23280.072*
H270.47880.00400.20600.070*
H280.55530.10180.18800.059*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O110.0431 (19)0.063 (2)0.0482 (19)0.0048 (17)0.0095 (18)0.0097 (19)
O210.0412 (18)0.056 (2)0.067 (2)0.0128 (16)0.0062 (19)0.0020 (19)
N110.039 (2)0.045 (2)0.0304 (19)0.0005 (18)0.0027 (18)0.0016 (18)
N120.050 (2)0.063 (3)0.040 (2)0.008 (2)0.007 (2)0.001 (2)
N130.046 (2)0.066 (3)0.052 (3)0.011 (2)0.009 (2)0.001 (2)
N210.0317 (18)0.0378 (19)0.056 (2)0.0048 (19)0.009 (2)0.004 (2)
N220.042 (2)0.042 (2)0.062 (3)0.0072 (18)0.002 (2)0.007 (2)
N230.046 (2)0.042 (2)0.066 (3)0.0039 (19)0.007 (2)0.006 (2)
C10.048 (3)0.033 (2)0.040 (3)0.002 (2)0.003 (2)0.005 (2)
C20.042 (2)0.037 (2)0.040 (3)0.008 (2)0.003 (2)0.003 (2)
C30.049 (3)0.048 (3)0.045 (3)0.005 (2)0.004 (2)0.001 (2)
C40.069 (3)0.051 (3)0.042 (3)0.005 (3)0.003 (3)0.007 (3)
C50.062 (3)0.041 (3)0.053 (3)0.000 (3)0.005 (3)0.000 (3)
C60.050 (3)0.045 (3)0.046 (3)0.006 (2)0.002 (3)0.002 (3)
C110.042 (3)0.039 (2)0.041 (3)0.004 (2)0.001 (3)0.004 (2)
C140.036 (3)0.050 (3)0.047 (3)0.001 (2)0.001 (2)0.002 (2)
C150.050 (3)0.057 (3)0.062 (3)0.010 (3)0.011 (3)0.002 (3)
C160.058 (3)0.057 (3)0.061 (3)0.004 (3)0.018 (3)0.011 (3)
C170.058 (3)0.058 (3)0.050 (3)0.014 (3)0.007 (3)0.013 (3)
C180.042 (3)0.050 (3)0.041 (3)0.009 (2)0.001 (2)0.003 (2)
C190.042 (3)0.035 (2)0.035 (2)0.003 (2)0.008 (2)0.003 (2)
C210.046 (3)0.044 (3)0.035 (2)0.008 (2)0.001 (2)0.001 (2)
C240.049 (3)0.039 (2)0.040 (3)0.001 (2)0.004 (3)0.004 (2)
C250.073 (4)0.043 (3)0.052 (3)0.001 (3)0.010 (3)0.004 (3)
C260.070 (4)0.056 (3)0.056 (3)0.017 (3)0.005 (3)0.003 (3)
C270.049 (3)0.072 (4)0.057 (3)0.011 (3)0.007 (3)0.008 (3)
C280.043 (3)0.057 (3)0.050 (3)0.001 (2)0.002 (2)0.015 (3)
C290.039 (2)0.046 (3)0.035 (2)0.002 (2)0.003 (2)0.004 (2)
Geometric parameters (Å, º) top
O11—C111.205 (5)C5—H50.95
O21—C211.203 (5)C6—H60.95
N11—C191.370 (5)C14—C151.386 (6)
N11—N121.385 (5)C14—C191.385 (6)
N11—C111.412 (5)C15—C161.366 (7)
N12—N131.281 (5)C15—H150.95
N13—C141.400 (6)C16—C171.398 (7)
N21—C291.383 (5)C16—H160.95
N21—N221.393 (5)C17—C181.375 (6)
N21—C211.419 (5)C17—H170.95
N22—N231.277 (5)C18—C191.396 (6)
N23—C241.401 (6)C18—H180.95
C1—C61.389 (6)C24—C291.378 (6)
C1—C21.402 (6)C24—C251.407 (6)
C1—C111.480 (6)C25—C261.365 (8)
C2—C31.395 (6)C25—H250.95
C2—C211.484 (6)C26—C271.392 (7)
C3—C41.372 (6)C26—H260.95
C3—H30.95C27—C281.368 (6)
C4—C51.372 (7)C27—H270.95
C4—H40.95C28—C291.392 (6)
C5—C61.380 (7)C28—H280.95
C19—N11—N12109.0 (3)C16—C15—H15121
C19—N11—C11127.6 (4)C14—C15—H15121
N12—N11—C11121.3 (4)C15—C16—C17120.3 (5)
N13—N12—N11109.6 (4)C15—C16—H16120
N12—N13—C14108.1 (4)C17—C16—H16120
C29—N21—N22109.4 (3)C18—C17—C16123.1 (5)
C29—N21—C21128.9 (3)C18—C17—H17119
N22—N21—C21121.6 (3)C16—C17—H17118
N23—N22—N21108.7 (4)C17—C18—C19116.1 (4)
N22—N23—C24108.8 (4)C17—C18—H18122
C6—C1—C2118.7 (4)C19—C18—H18122
C6—C1—C11122.6 (4)N11—C19—C14104.6 (4)
C2—C1—C11118.6 (4)N11—C19—C18134.4 (4)
C3—C2—C1119.6 (4)C14—C19—C18120.9 (4)
C3—C2—C21115.3 (4)O21—C21—N21118.1 (4)
C1—C2—C21125.1 (4)O21—C21—C2124.4 (4)
C4—C3—C2120.1 (4)N21—C21—C2117.1 (4)
C4—C3—H3120C29—C24—N23109.1 (4)
C2—C3—H3120C29—C24—C25121.7 (5)
C5—C4—C3120.9 (5)N23—C24—C25129.0 (4)
C5—C4—H4119C26—C25—C24116.2 (5)
C3—C4—H4120C26—C25—H25122
C4—C5—C6119.5 (5)C24—C25—H25122
C4—C5—H5120C25—C26—C27121.5 (5)
C6—C5—H5120C25—C26—H26120
C5—C6—C1121.2 (5)C27—C26—H26119
C5—C6—H6120C28—C27—C26122.8 (5)
C1—C6—H6119C28—C27—H27119
O11—C11—N11119.5 (4)C26—C27—H27119
O11—C11—C1123.3 (4)C27—C28—C29116.2 (5)
N11—C11—C1117.2 (4)C27—C28—H28122
C15—C14—C19122.0 (5)C29—C28—H28122
C15—C14—N13129.3 (5)C24—C29—N21104.0 (3)
C19—C14—N13108.7 (4)C24—C29—C28121.5 (4)
C16—C15—C14117.5 (5)N21—C29—C28134.5 (4)
C19—N11—N12—N130.8 (5)N12—N11—C19—C18178.1 (4)
C11—N11—N12—N13165.9 (4)C11—N11—C19—C1818.1 (8)
N11—N12—N13—C141.0 (5)C15—C14—C19—N11178.6 (4)
C29—N21—N22—N231.0 (6)N13—C14—C19—N110.2 (5)
C21—N21—N22—N23178.0 (4)C15—C14—C19—C183.3 (7)
N21—N22—N23—C240.5 (6)N13—C14—C19—C18177.9 (4)
C6—C1—C2—C30.1 (6)C17—C18—C19—N11179.3 (5)
C11—C1—C2—C3176.0 (4)C17—C18—C19—C143.2 (6)
C6—C1—C2—C21179.7 (4)C29—N21—C21—O216.3 (7)
C11—C1—C2—C214.4 (6)N22—N21—C21—O21177.2 (4)
C1—C2—C3—C40.2 (6)C29—N21—C21—C2166.9 (4)
C21—C2—C3—C4179.7 (4)N22—N21—C21—C29.5 (6)
C2—C3—C4—C50.2 (7)C3—C2—C21—O2153.4 (6)
C3—C4—C5—C60.6 (7)C1—C2—C21—O21127.0 (5)
C4—C5—C6—C10.6 (7)C3—C2—C21—N21119.4 (4)
C2—C1—C6—C50.3 (7)C1—C2—C21—N2160.2 (6)
C11—C1—C6—C5175.5 (4)N22—N23—C24—C290.1 (6)
C19—N11—C11—O110.0 (7)N22—N23—C24—C25175.7 (5)
N12—N11—C11—O11162.0 (4)C29—C24—C25—C261.9 (8)
C19—N11—C11—C1178.4 (4)N23—C24—C25—C26177.0 (6)
N12—N11—C11—C116.3 (6)C24—C25—C26—C271.1 (9)
C6—C1—C11—O11135.2 (5)C25—C26—C27—C281.0 (9)
C2—C1—C11—O1140.6 (6)C26—C27—C28—C291.5 (8)
C6—C1—C11—N1146.5 (6)N23—C24—C29—N210.6 (5)
C2—C1—C11—N11137.7 (4)C25—C24—C29—N21176.6 (5)
N12—N13—C14—C15178.0 (5)N23—C24—C29—C28178.6 (5)
N12—N13—C14—C190.8 (5)C25—C24—C29—C282.6 (8)
C19—C14—C15—C161.4 (7)N22—N21—C29—C241.0 (5)
N13—C14—C15—C16179.9 (5)C21—N21—C29—C24177.7 (4)
C14—C15—C16—C170.3 (7)N22—N21—C29—C28178.1 (5)
C15—C16—C17—C180.2 (8)C21—N21—C29—C281.3 (9)
C16—C17—C18—C191.6 (7)C27—C28—C29—C242.3 (8)
N12—N11—C19—C140.3 (5)C27—C28—C29—N21176.6 (5)
C11—N11—C19—C14164.2 (4)

Experimental details

Crystal data
Chemical formulaC20H12N6O2
Mr368.36
Crystal system, space groupOrthorhombic, P212121
Temperature (K)295
a, b, c (Å)10.744 (5), 22.193 (4), 7.079 (5)
V3)1687.9 (14)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.38 × 0.25 × 0.20
Data collection
DiffractometerRigaku AFC-7R
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)'] reflections
2231, 2231, 992
Rint0.000
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.138, 0.89
No. of reflections2231
No. of parameters254
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.18, 0.18

Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1999a), MSC/AFC Diffractometer Control Software, TEXSAN for Windows (Molecular Structure Corporation, 1999b), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON for Windows (Spek, 1999), TEXSAN for Windows.

 

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