Buy article online - an online subscription or single-article purchase is required to access this article.
Hexamethylenetetramine, C
6H
12N
4, and ferrocenecarboxylic acid, C
11H
10FeO
2, form a 1:2 adduct, (I), which is a salt,
viz. hexamethylenetetraminium(2+) bis(ferrocenecarboxylate), (C
6H
14N
4)[Fe(C
5H
5)(C
6H
4O
2)]
2. The dication in (I) is disordered with two orientations at a site of
mm2 symmetry in space group
Fmm2, while the anion lies across a mirror plane with its unsubstituted cyclopentadienyl ring disordered over two sets of sites. With ferrocene-1,1'-dicarboxylic acid, C
12H
10FeO
4, hexamethylenetetramine forms a 1:1 adduct, (II), in which both components are neutral,
viz. hexamethylenetetramine-ferrocene-1,1'-dicarboxylic acid (1/1), [Fe(C
6H
5O
2)
2]·C
6H
12N
4. The amine component in (II) is disordered with two orientations at a site of
mm2 symmetry in space group
Cmcm, while the acid component is disordered with two orientations at a site of 2/
m symmetry. The components in (I) are linked into a finite three-ion aggregate by a single N-H
O hydrogen bond, while the components of (II) are linked into continuous chains by a single O-H
N hydrogen bond.
Supporting information
CCDC references: 217125; 217126
Stoichiometric quantities of HMTA and the appropriate acid were separately dissolved in tetrahydrofuran; the solutions of amine and acid were mixed and the mixtures were then set aside to crystallize, producing analytically pure samples of (I) and (II), respectively. Analysis found for (I): C 56.4, H 5.0, N 9.3%; C28H32Fe2N4O4 requires: C 56.0, H 5.4, N 9.3%; found for (II): C 51.7, H 5.4, N 13.3%; C18H22FeN4O4 requires: C 52.2, H 5.4, N 13.5%. Crystals suitable for single-crystal X-ray diffraction were selected directly from the analytical samples.
Crystals of both (I) and (II) are orthorhombic. For (I), the systematic absences permitted F222, Fmm2 and Fmmm as possible space groups, but only Fmm2 allowed a successful refinement, with both the C11H9FeO2 and C6H14N4 moieties being disordered. Cyclopentadienyl ring C21–C25 is disordered and was allowed for using the SHELXL97 (Sheldrick, 1997) AFIX 59 command during the refinement. There was no evidence for an H atom being bonded to O1, but there was some residual density adjacent to N1 directed towards O1; accordingly, the SHELXL97 HFIX 13 command was used to generate a riding H atom on N1, with N—H = 0.93 Å. For (II), the systematic absences permitted Cmc21, C2cm (= Ama2, No. 40) and Cmcm as possible space groups. Only Cmcm allowed a successful refinement, with both the C12H10FeO4 and C6H12N4 moieties being disordered. Investigation of the Cmc21 and C2cm possibilities led to refinements with rather higher R values than the Cmcm refinement, despite the greater number of parameters; for these refinements, the ADDSYM option in PLATON (Spek, 2003) reported a 100% fit for space group Cmcm. However, we emphasize that regardless of which one of these space groups is considered, the overall structure is unchanged. There was no evidence for an H atom being bonded to N1, but there was some residual density adjacent to O1 directed towards N1; accordingly the SHELXL97 HFIX 147 command was used to generate a riding H atom on O1, with O—H = 0.84 Å. In both structures, all H atoms bonded to C atoms were identified in difference maps and they were treated as riding atoms, with C—H distances of 0.95 Å (cyclopentadienyl) or 0.99 Å (CH2). For compound (I), the Flack (1983) parameter of 0.33 (4) indicated racemic twinning.
For both compounds, data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
(I) Hexamethylenetetramine–ferrocenecarboxylic acid (1/2)
top
Crystal data top
(C6H14N4)[Fe(C5H5)(C6H4O2)]2 | F(000) = 1248 |
Mr = 600.28 | Dx = 1.563 Mg m−3 |
Orthorhombic, Fmm2 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: F 2 -2 | Cell parameters from 1351 reflections |
a = 9.9496 (8) Å | θ = 2.6–27.4° |
b = 36.295 (3) Å | µ = 1.18 mm−1 |
c = 7.0643 (6) Å | T = 150 K |
V = 2551.1 (4) Å3 | Block, orange |
Z = 4 | 0.28 × 0.26 × 0.22 mm |
Data collection top
Nonius KappaCCD diffractometer | 1351 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 1197 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.055 |
ϕ scans, and ω scans with κ offsets | θmax = 27.4°, θmin = 2.6° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = −12→12 |
Tmin = 0.709, Tmax = 0.775 | k = −46→45 |
2539 measured reflections | l = −8→8 |
Refinement top
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.044 | w = 1/[σ2(Fo2)2 + 2.01P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.099 | (Δ/σ)max < 0.001 |
S = 1.06 | Δρmax = 0.40 e Å−3 |
1351 reflections | Δρmin = −0.32 e Å−3 |
129 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.0031 (6) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983), 507 Friedel pairs |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.33 (4) |
Crystal data top
(C6H14N4)[Fe(C5H5)(C6H4O2)]2 | V = 2551.1 (4) Å3 |
Mr = 600.28 | Z = 4 |
Orthorhombic, Fmm2 | Mo Kα radiation |
a = 9.9496 (8) Å | µ = 1.18 mm−1 |
b = 36.295 (3) Å | T = 150 K |
c = 7.0643 (6) Å | 0.28 × 0.26 × 0.22 mm |
Data collection top
Nonius KappaCCD diffractometer | 1351 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 1197 reflections with I > 2σ(I) |
Tmin = 0.709, Tmax = 0.775 | Rint = 0.055 |
2539 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.044 | H-atom parameters constrained |
wR(F2) = 0.099 | Δρmax = 0.40 e Å−3 |
S = 1.06 | Δρmin = −0.32 e Å−3 |
1351 reflections | Absolute structure: Flack (1983), 507 Friedel pairs |
129 parameters | Absolute structure parameter: 0.33 (4) |
1 restraint | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Fe1 | 0.5000 | 0.167884 (17) | 0.44306 (13) | 0.0281 (2) | |
O1 | 0.6105 (4) | 0.08161 (9) | 0.1745 (6) | 0.0835 (14) | |
C11 | 0.5000 | 0.11197 (12) | 0.4231 (13) | 0.0264 (12) | |
C12 | 0.3854 (4) | 0.12447 (12) | 0.5256 (7) | 0.0456 (11) | |
C13 | 0.4294 (5) | 0.14382 (13) | 0.6827 (8) | 0.0660 (15) | |
C14 | 0.5000 | 0.09063 (14) | 0.2478 (9) | 0.0510 (18) | |
C21 | 0.5496 (15) | 0.1897 (3) | 0.1825 (15) | 0.050 (7) | 0.50 |
C22 | 0.6262 (8) | 0.2067 (4) | 0.322 (2) | 0.061 (7) | 0.50 |
C23 | 0.5388 (8) | 0.2228 (2) | 0.4514 (19) | 0.069 (12) | 0.50 |
C24 | 0.4081 (13) | 0.2157 (5) | 0.392 (2) | 0.072 (9) | 0.50 |
C25 | 0.4147 (18) | 0.1952 (3) | 0.2257 (15) | 0.049 (5) | 0.50 |
N1 | 0.5299 (4) | 0.03214 (14) | −0.1017 (7) | 0.0229 (18) | 0.50 |
N2 | 0.3812 (6) | 0.00777 (17) | −0.3445 (9) | 0.032 (2) | 0.50 |
C1A | 0.4104 (9) | 0.0399 (2) | −0.2211 (12) | 0.0312 (18) | 0.50 |
C1B | 0.3548 (9) | 0.0241 (2) | −0.2294 (12) | 0.0331 (19) | 0.50 |
C2 | 0.5000 | 0.0000 | 0.0156 (11) | 0.0281 (16) | |
C3 | 0.5000 | 0.0000 | −0.4601 (11) | 0.0399 (18) | |
H12 | 0.2942 | 0.1202 | 0.4918 | 0.055* | |
H13 | 0.3736 | 0.1552 | 0.7749 | 0.079* | |
H21 | 0.5868 | 0.1764 | 0.0793 | 0.060* | 0.50 |
H22 | 0.7216 | 0.2063 | 0.3272 | 0.073* | 0.50 |
H23 | 0.5737 | 0.2355 | 0.5581 | 0.083* | 0.50 |
H24 | 0.3336 | 0.2265 | 0.4554 | 0.086* | 0.50 |
H25 | 0.3375 | 0.1893 | 0.1529 | 0.059* | 0.50 |
H1 | 0.5492 | 0.0524 | −0.0257 | 0.027* | 0.50 |
H11A | 0.3319 | 0.0450 | −0.1393 | 0.037* | 0.50 |
H11B | 0.4275 | 0.0619 | −0.3002 | 0.037* | 0.50 |
H11C | 0.2730 | 0.0198 | −0.1527 | 0.040* | 0.50 |
H11D | 0.3380 | 0.0456 | −0.3121 | 0.040* | 0.50 |
H2A | 0.5780 | −0.0054 | 0.0979 | 0.034* | 0.25 |
H2B | 0.4220 | 0.0054 | 0.0979 | 0.034* | 0.25 |
H3A | 0.5187 | 0.0214 | −0.5426 | 0.048* | 0.25 |
H3B | 0.4813 | −0.0214 | −0.5426 | 0.048* | 0.25 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Fe1 | 0.0345 (4) | 0.0219 (3) | 0.0280 (4) | 0.000 | 0.000 | −0.0018 (5) |
O1 | 0.108 (3) | 0.049 (2) | 0.093 (3) | −0.0305 (19) | 0.064 (3) | −0.037 (2) |
C11 | 0.031 (2) | 0.022 (2) | 0.026 (4) | 0.000 | 0.000 | 0.004 (3) |
C12 | 0.039 (2) | 0.030 (2) | 0.067 (3) | 0.0005 (17) | 0.0148 (18) | 0.0083 (19) |
C13 | 0.117 (4) | 0.040 (3) | 0.041 (2) | 0.001 (2) | 0.036 (3) | −0.002 (2) |
C14 | 0.098 (5) | 0.015 (3) | 0.040 (4) | 0.000 | 0.000 | 0.001 (2) |
C21 | 0.083 (18) | 0.036 (5) | 0.031 (5) | −0.002 (5) | 0.004 (6) | 0.007 (4) |
C22 | 0.024 (5) | 0.054 (11) | 0.10 (2) | −0.014 (6) | 0.008 (8) | 0.044 (12) |
C23 | 0.12 (3) | 0.018 (3) | 0.075 (7) | −0.006 (4) | −0.015 (14) | −0.004 (7) |
C24 | 0.064 (14) | 0.076 (15) | 0.076 (15) | 0.040 (15) | 0.032 (15) | 0.028 (10) |
C25 | 0.042 (8) | 0.054 (10) | 0.051 (10) | −0.016 (9) | −0.013 (10) | 0.016 (7) |
N1 | 0.020 (5) | 0.024 (3) | 0.024 (4) | −0.0047 (18) | −0.004 (2) | 0.0002 (18) |
N2 | 0.051 (3) | 0.024 (7) | 0.021 (3) | −0.004 (3) | −0.007 (2) | −0.001 (3) |
C1A | 0.043 (5) | 0.023 (4) | 0.027 (4) | 0.002 (3) | −0.008 (4) | −0.001 (3) |
C1B | 0.036 (5) | 0.034 (5) | 0.029 (5) | 0.006 (4) | −0.013 (4) | 0.003 (4) |
C2 | 0.038 (4) | 0.027 (4) | 0.020 (3) | 0.000 | 0.000 | 0.000 |
C3 | 0.061 (5) | 0.033 (4) | 0.025 (4) | 0.000 | 0.000 | 0.000 |
Geometric parameters (Å, º) top
Fe1—C24 | 1.995 (17) | C24—C25 | 1.391 (9) |
Fe1—C25 | 2.016 (12) | C24—H24 | 0.95 |
Fe1—C13 | 2.030 (5) | C25—H25 | 0.95 |
Fe1—C23 | 2.031 (8) | N1—C1A | 1.484 (10) |
Fe1—C12 | 2.031 (4) | N1—C1Bi | 1.489 (9) |
Fe1—C11 | 2.034 (5) | N1—C2 | 1.461 (7) |
Fe1—C21 | 2.063 (11) | N1—H1 | 0.93 |
O1—C14 | 1.258 (5) | N2—C1A | 1.484 (10) |
C11—C12 | 1.425 (7) | N2—C1Bii | 1.438 (10) |
C11—C14 | 1.461 (10) | N2—C3 | 1.465 (8) |
C12—C13 | 1.385 (7) | C1A—H11A | 0.99 |
C12—H12 | 0.95 | C1A—H11B | 0.99 |
C13—C13i | 1.405 (11) | C1B—N2ii | 1.438 (10) |
C13—H13 | 0.95 | C1B—N1i | 1.489 (9) |
C14—O1i | 1.258 (5) | C1B—H11C | 0.99 |
C21—C22 | 1.391 (9) | C1B—H11D | 0.99 |
C21—C25 | 1.391 (9) | C2—N1iii | 1.461 (7) |
C21—H21 | 0.95 | C2—H2A | 0.99 |
C22—C23 | 1.391 (9) | C2—H2B | 0.99 |
C22—H22 | 0.95 | C3—N2iii | 1.465 (8) |
C23—C24 | 1.391 (9) | C3—H3A | 0.99 |
C23—H23 | 0.95 | C3—H3B | 0.99 |
| | | |
C12i—C11—C12 | 106.3 (7) | C2—N1—H1 | 110.2 |
C12i—C11—C14 | 126.8 (4) | C1A—N1—H1 | 110.2 |
C12—C11—C14 | 126.8 (4) | C1Bi—N1—H1 | 110.2 |
C13—C12—C11 | 108.4 (5) | C3—N2—C1A | 108.7 (5) |
C13—C12—H12 | 125.8 | C1A—N2—C1Aii | 113.7 (7) |
C11—C12—H12 | 125.8 | N2—C1A—N1 | 110.0 (6) |
C12—C13—C13i | 108.4 (3) | N2—C1A—H11A | 109.7 |
C12—C13—H13 | 125.8 | N1—C1A—H11A | 109.7 |
C13i—C13—H13 | 125.8 | N2—C1A—H11B | 109.7 |
O1i—C14—O1 | 121.7 (6) | N1—C1A—H11B | 109.7 |
O1i—C14—C11 | 119.1 (3) | H11A—C1A—H11B | 108.2 |
O1—C14—C11 | 119.1 (3) | N2ii—C1B—N1i | 111.0 (6) |
C22—C21—C25 | 108.0 | N2ii—C1B—H11C | 109.4 |
C22—C21—H21 | 123.8 | N1i—C1B—H11C | 109.4 |
C25—C21—H21 | 128.2 | N2ii—C1B—H11D | 109.4 |
C21—C22—C23 | 108.0 | N1i—C1B—H11D | 109.4 |
C21—C22—H22 | 124.7 | H11C—C1B—H11D | 108.0 |
C23—C22—H22 | 127.3 | N1iii—C2—N1 | 110.9 (6) |
C24—C23—C22 | 108.0 | N1iii—C2—H2A | 109.5 |
C24—C23—H23 | 132.2 | N1—C2—H2A | 109.5 |
C22—C23—H23 | 119.8 | N1iii—C2—H2B | 109.5 |
C23—C24—C25 | 108.0 | N1—C2—H2B | 109.5 |
C23—C24—H24 | 120.7 | H2A—C2—H2B | 108.0 |
C25—C24—H24 | 131.0 | N2—C3—N2iii | 112.2 (7) |
C24—C25—C21 | 108.0 | N2—C3—H3A | 109.2 |
C24—C25—H25 | 122.7 | N2iii—C3—H3A | 109.2 |
C21—C25—H25 | 128.9 | N2—C3—H3B | 109.2 |
C2—N1—C1A | 108.1 (5) | N2iii—C3—H3B | 109.2 |
C2—N1—C1Bi | 110.1 (5) | H3A—C3—H3B | 107.9 |
C1A—N1—C1Bi | 108.0 (5) | | |
Symmetry codes: (i) −x+1, y, z; (ii) x, −y, z; (iii) −x+1, −y, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.93 | 1.87 | 2.770 (6) | 162 |
(II) Hexamethylenetetramine–ferrocene-1,1'-dicarboxylic acid (1/1)
top
Crystal data top
[Fe(C6H5O2)2]·C6H12N4 | F(000) = 864 |
Mr = 414.25 | Dx = 1.585 Mg m−3 |
Orthorhombic, Cmcm | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2c 2 | Cell parameters from 895 reflections |
a = 10.0096 (4) Å | θ = 2.6–25.0° |
b = 7.1396 (2) Å | µ = 0.90 mm−1 |
c = 24.2841 (8) Å | T = 150 K |
V = 1735.45 (10) Å3 | Plate, orange |
Z = 4 | 0.28 × 0.25 × 0.06 mm |
Data collection top
Nonius KappaCCD diffractometer | 836 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 671 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.045 |
ϕ scans, and ω scans with κ offsets | θmax = 25.0°, θmin = 2.6° |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | h = 0→11 |
Tmin = 0.786, Tmax = 0.948 | k = 0→8 |
6092 measured reflections | l = −28→0 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.13 | w = 1/[σ2(Fo2) + (0.0024P)2 + 3.0941P] where P = (Fo2 + 2Fc2)/3 |
836 reflections | (Δ/σ)max < 0.001 |
103 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.45 e Å−3 |
Crystal data top
[Fe(C6H5O2)2]·C6H12N4 | V = 1735.45 (10) Å3 |
Mr = 414.25 | Z = 4 |
Orthorhombic, Cmcm | Mo Kα radiation |
a = 10.0096 (4) Å | µ = 0.90 mm−1 |
b = 7.1396 (2) Å | T = 150 K |
c = 24.2841 (8) Å | 0.28 × 0.25 × 0.06 mm |
Data collection top
Nonius KappaCCD diffractometer | 836 independent reflections |
Absorption correction: multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | 671 reflections with I > 2σ(I) |
Tmin = 0.786, Tmax = 0.948 | Rint = 0.045 |
6092 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.13 | Δρmax = 0.27 e Å−3 |
836 reflections | Δρmin = −0.45 e Å−3 |
103 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Fe1 | 0.5206 (4) | 0.5000 | 0.5000 | 0.0220 (9) | 0.50 |
O1 | 0.3902 (2) | 0.2301 (3) | 0.62671 (7) | 0.0677 (7) | |
C11 | 0.5141 (11) | 0.4793 (4) | 0.58310 (10) | 0.0176 (15) | 0.50 |
C12 | 0.6353 (7) | 0.5654 (9) | 0.5677 (3) | 0.0216 (14) | 0.50 |
C13 | 0.6044 (3) | 0.7307 (6) | 0.5385 (2) | 0.032 (2) | 0.50 |
C14 | 0.4641 (3) | 0.7467 (7) | 0.5359 (2) | 0.027 (3) | 0.50 |
C15 | 0.4082 (7) | 0.5914 (10) | 0.5634 (3) | 0.0284 (18) | 0.50 |
C16 | 0.5000 | 0.3025 (5) | 0.61384 (12) | 0.0437 (10) | |
N1 | 0.4712 (4) | −0.0449 (5) | 0.70095 (12) | 0.0200 (15) | 0.50 |
N2 | 0.3805 (3) | −0.2863 (5) | 0.76188 (14) | 0.0255 (13) | 0.50 |
C1A | 0.3549 (6) | −0.1681 (7) | 0.7136 (2) | 0.0280 (12) | 0.50 |
C1B | 0.4103 (6) | −0.1645 (8) | 0.6909 (2) | 0.0270 (12) | 0.50 |
C2 | 0.5000 | 0.0721 (5) | 0.7500 | 0.0223 (9) | |
C3 | 0.5000 | −0.4006 (6) | 0.7500 | 0.0318 (11) | |
H1 | 0.4037 | 0.1352 | 0.6464 | 0.102* | 0.50 |
H12 | 0.7225 | 0.5201 | 0.5756 | 0.026* | 0.50 |
H13 | 0.6671 | 0.8161 | 0.5233 | 0.039* | 0.50 |
H14 | 0.4156 | 0.8449 | 0.5186 | 0.032* | 0.50 |
H15 | 0.3156 | 0.5666 | 0.5680 | 0.034* | 0.50 |
H11A | 0.2751 | −0.0896 | 0.7206 | 0.034* | 0.50 |
H12A | 0.3358 | −0.2487 | 0.6814 | 0.034* | 0.50 |
H11B | 0.3320 | −0.0838 | 0.6834 | 0.032* | 0.50 |
H12B | 0.4264 | −0.2429 | 0.6580 | 0.032* | 0.50 |
H2A | 0.4222 | 0.1536 | 0.7577 | 0.027* | 0.25 |
H2B | 0.5778 | 0.1536 | 0.7423 | 0.027* | 0.25 |
H3A | 0.5187 | −0.4823 | 0.7820 | 0.038* | 0.25 |
H3B | 0.4813 | −0.4823 | 0.7180 | 0.038* | 0.25 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Fe1 | 0.036 (3) | 0.0161 (3) | 0.0136 (3) | 0.000 | 0.000 | 0.0004 (3) |
O1 | 0.0916 (16) | 0.0698 (14) | 0.0417 (11) | −0.0377 (12) | 0.0030 (11) | 0.0244 (10) |
C11 | 0.017 (5) | 0.0220 (15) | 0.0132 (13) | 0.004 (3) | −0.002 (3) | −0.0022 (11) |
C12 | 0.007 (4) | 0.036 (3) | 0.022 (3) | −0.010 (2) | −0.002 (2) | −0.008 (2) |
C13 | 0.053 (7) | 0.021 (2) | 0.023 (2) | −0.020 (3) | 0.009 (3) | −0.0061 (19) |
C14 | 0.031 (9) | 0.024 (2) | 0.027 (2) | 0.011 (2) | −0.004 (3) | −0.0003 (16) |
C15 | 0.008 (6) | 0.044 (4) | 0.033 (3) | −0.001 (3) | 0.008 (3) | −0.014 (3) |
C16 | 0.089 (3) | 0.0288 (17) | 0.0127 (14) | 0.000 | 0.000 | −0.0007 (13) |
N1 | 0.019 (5) | 0.0237 (16) | 0.0176 (14) | −0.0016 (17) | −0.0005 (14) | 0.0029 (11) |
N2 | 0.0359 (19) | 0.0210 (15) | 0.019 (4) | −0.0094 (14) | 0.0004 (15) | 0.0012 (15) |
C1A | 0.030 (3) | 0.026 (3) | 0.028 (3) | −0.011 (2) | −0.005 (2) | 0.000 (2) |
C1B | 0.028 (3) | 0.029 (3) | 0.024 (3) | −0.001 (3) | −0.005 (2) | 0.004 (2) |
C2 | 0.031 (2) | 0.0136 (18) | 0.023 (2) | 0.000 | 0.000 | 0.000 |
C3 | 0.050 (3) | 0.016 (2) | 0.029 (2) | 0.000 | 0.000 | 0.000 |
Geometric parameters (Å, º) top
Fe1—Fe1i | 0.412 (6) | C14—H14 | 0.95 |
Fe1—C11 | 2.024 (2) | C15—H15 | 0.95 |
Fe1—C12 | 2.059 (8) | N1—C1A | 1.492 (6) |
Fe1—C13 | 2.071 (5) | N1—C1Bii | 1.481 (7) |
Fe1—C14 | 2.045 (6) | N1—C2 | 1.483 (4) |
Fe1—C15 | 2.015 (8) | N2—C1A | 1.467 (6) |
O1—C16 | 1.254 (2) | N2—C1Biii | 1.469 (6) |
O1—H1 | 0.84 | N2—C3 | 1.476 (4) |
C11—C15 | 1.411 (2) | C1A—H11A | 0.99 |
C11—C12 | 1.411 (2) | C1A—H12A | 0.99 |
C11—C16 | 1.473 (4) | C1B—H11B | 0.99 |
C12—C13 | 1.411 (2) | C1B—H12B | 0.99 |
C12—H12 | 0.95 | C2—H2A | 0.99 |
C13—C14 | 1.411 (2) | C2—H2B | 0.99 |
C13—H13 | 0.95 | C3—H3A | 0.99 |
C14—C15 | 1.411 (2) | C3—H3B | 0.99 |
| | | |
C16—O1—H1 | 109.5 | C1A—N2—C1Biii | 108.5 (3) |
C15—C11—C12 | 108.0 | C1A—N2—C3 | 107.7 (4) |
C15—C11—C16 | 125.8 (7) | C1Biii—N2—C3 | 108.4 (3) |
C12—C11—C16 | 126.2 (7) | N2—C1A—N1 | 111.5 (4) |
C11—C12—C13 | 108.0 | N2—C1A—H11A | 109.3 |
C11—C12—H12 | 126.0 | N1—C1A—H11A | 109.3 |
C13—C12—H12 | 126.0 | N2—C1A—H12A | 109.3 |
C12—C13—C14 | 108.0 | N1—C1A—H12A | 109.3 |
C12—C13—H13 | 126.0 | H11A—C1A—H12A | 108.0 |
C14—C13—H13 | 126.0 | N2iii—C1B—N1ii | 112.1 (4) |
C15—C14—C13 | 108.0 | N2iii—C1B—H11B | 109.2 |
C15—C14—H14 | 126.0 | N1ii—C1B—H12B | 109.2 |
C13—C14—H14 | 126.0 | H11B—C1B—H12B | 107.9 |
C11—C15—C14 | 108.0 | N1—C2—N1iv | 111.5 (3) |
C11—C15—H15 | 126.0 | N1—C2—H2A | 109.3 |
C14—C15—H15 | 126.0 | N1—C2—H2B | 109.3 |
O1—C16—O1ii | 122.4 (3) | H2A—C2—H2B | 108.0 |
O1—C16—C11ii | 113.3 (5) | N2iv—C3—N2 | 112.9 (4) |
O1—C16—C11 | 124.3 (5) | N2—C3—H3A | 109.0 |
C1Bii—N1—C2 | 107.5 (4) | N2—C3—H3B | 109.0 |
C1Bii—N1—C1A | 108.6 (3) | H3A—C3—H3B | 107.8 |
C2—N1—C1A | 108.5 (3) | | |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, y, z; (iii) x, y, −z+3/2; (iv) −x+1, y, −z+3/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.84 | 1.97 | 2.786 (3) | 165 |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | (C6H14N4)[Fe(C5H5)(C6H4O2)]2 | [Fe(C6H5O2)2]·C6H12N4 |
Mr | 600.28 | 414.25 |
Crystal system, space group | Orthorhombic, Fmm2 | Orthorhombic, Cmcm |
Temperature (K) | 150 | 150 |
a, b, c (Å) | 9.9496 (8), 36.295 (3), 7.0643 (6) | 10.0096 (4), 7.1396 (2), 24.2841 (8) |
V (Å3) | 2551.1 (4) | 1735.45 (10) |
Z | 4 | 4 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 1.18 | 0.90 |
Crystal size (mm) | 0.28 × 0.26 × 0.22 | 0.28 × 0.25 × 0.06 |
|
Data collection |
Diffractometer | Nonius KappaCCD diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) | Multi-scan (DENZO-SMN; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.709, 0.775 | 0.786, 0.948 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2539, 1351, 1197 | 6092, 836, 671 |
Rint | 0.055 | 0.045 |
(sin θ/λ)max (Å−1) | 0.647 | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.099, 1.06 | 0.032, 0.073, 1.13 |
No. of reflections | 1351 | 836 |
No. of parameters | 129 | 103 |
No. of restraints | 1 | 0 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.40, −0.32 | 0.27, −0.45 |
Absolute structure | Flack (1983), 507 Friedel pairs | ? |
Absolute structure parameter | 0.33 (4) | ? |
Selected bond lengths (Å) for (I) topN1—C1A | 1.484 (10) | N2—C1A | 1.484 (10) |
N1—C1Bi | 1.489 (9) | N2—C1Bii | 1.438 (10) |
N1—C2 | 1.461 (7) | N2—C3 | 1.465 (8) |
Symmetry codes: (i) −x+1, y, z; (ii) x, −y, z. |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.93 | 1.87 | 2.770 (6) | 162 |
Selected bond lengths (Å) for (II) topN1—C1A | 1.492 (6) | N2—C1A | 1.467 (6) |
N1—C1Bi | 1.481 (7) | N2—C1Bii | 1.469 (6) |
N1—C2 | 1.483 (4) | N2—C3 | 1.476 (4) |
Symmetry codes: (i) −x+1, y, z; (ii) x, y, −z+3/2. |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.84 | 1.97 | 2.786 (3) | 165 |
Subscribe to Acta Crystallographica Section C: Structural Chemistry
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.
The stoichiometric adducts formed between ferrocene-1,1'-dicarboxylic acid, [Fe(C5H4COOH)2] and a wide variety of amines are all salts, some of which contain the monoanion [Fe(C5H4COOH)(C5H4COO−)] (Braga et al., 2000, 2002; Zakaria et al., 2002), and others of which contain the dianion [Fe(C5H4COO−)2] (Braga et al., 2000, 2001; Zakaria et al., 2002). On the other hand, the sole such adduct reported to date formed by ferrocenecarboxylic acid, [(C5H5)Fe(C5H4COOH)], is the 1:2 adduct formed with the cage type diamine 1,4-diazabicyclo[2.2.2]octane (C6H12N2, DABCO), which contain two neutral components, viz. C6H12N2·2C11H10FeO2, linked by O—H···N hydrogen bonds (Zakaria et al., 2001). By contrast, the adduct formed between DABCO and ferrocene-1,1'-dicarboxylic acid is the salt [(C6H12N2)H]+·[Fe(C5H4COOH)(C5H4COO−)], in which the components are linked into chains by a combination of N—H···O and O—H···N hydrogen bonds (Zakaria et al., 2002; Braga et al., 2002).
We have now investigated the adducts formed by the same two ferrocene acids with a second cage-type amine, hexamethylenetetramine (C6H12N4, HMTA), where we find a reversal of the behaviour observed in the corresponding DABCO adducts. With HMTA, ferrocenecarboxylic acid forms a salt-type 1:2 adduct [(C6H12N4)H2]2+·[Fe(C5H4COOH)(C5H4COO−)]2, (I), containing the uncommon diprotonated form of HMTA, while ferrocene-1,1'-dicarboxylic acid forms a 1:1 adduct, (II), in which both components are neutral, thus C6H12N4·[Fe(C5H4COOH)2].
In the salt (I), the anion lies across a mirror plane in space group Fmm2, selected for the reference anion as that at x = 0.5. The iron, and the substituted cyclopentadienyl ring are fully ordered, but the unsubstituted ring is disordered over two sets of sites both having a occupancy 0.5 (Fig. 1a). The cation at a site of mm2 (C2v) symmetry, with the atoms C2 and C3 (Fig. 1 b) lying fully ordered on the twofold axis along (1/2, 0, z), but all of the other non-H atoms of the cation are disordered over two sets of sites related by the mirror planes at x = 0.5 and y = 0. Hence the two alternative orientations of the HMTA cage appear to be intimately interwoven (Fig. 2).
The bond distances in the anion of (I) show no unexpected features. In the cation, the ranges of the C—N distances involving the protonated N1 and the unprotonated N2 overlap (Table 1), and there is no significant difference between the mean values for the two types. By contrast, in the monoprotonated HMTA cation, [(C6H12N4)H]+, it is possible to discern three distinct ranges of C—N distances, which indicate considerable progress along the acid-induced decomposition pathway which leads eventually to complete break-up of the HMTA cage (Lough et al., 2000). This diprotonated HMTA dication is unusual, and only one other example is recorded in the February 2003 release of the Cambridge Structural Database (CSD; Allen, 2002). In this example, containing a polymolybdate anion 2Na+.2[(C6H12N4)H2]2+·[Mo7O24]6−·9H2O [CSD refcode XOXQOQ; Yang et al., 2002)], no H-atom coordinates were reported nor is it clear how the H atoms were located. Nevertheless, two of the four N atoms of the HMTA cage in XOXQOQ are within hydrogen-bonding distance of an O atom.
The component ions of (I) are linked by a single N—H···O bond (Table 2) to form a finite three-component aggregate (Fig. 3), but there are neither C—H···X or X—H···π(cyclopentadienyl) (X = N or O) interactions between these aggregates. By contrast in the analogous DABCO adduct, the three-component aggregates are linked into sheets by a series of C—H···O hydrogen bonds (Zakaria et al., 2001).
The acid component of compound (II) lies at a site of 2/m (C2 h) symmetry in space group Cmcm, selected as that at (1/2, 1/2, 1/2), and it is disordered over two sets of sites related by mirror symmetry such that only the carboxyl C16 is common to the two orientations (Fig. 4a). An individual molecule of the acid component therefore exhibits only twofold rotational symmetry. The neutral amine component of (II), like the cation in (I), lies at a site of mm2 (C2v) symmetry, with atoms C2 and C3 lying on the twofold axis along (1/2, y, 3/4) (Fig. 4 b). The amine is disordered over two sets of sites related by the mirror plane at x = 0.5 (Fig. 5), so that its behaviour is very similar to that of the cation in (I). Again there is no significant difference between the two types of C—N bond -distance (Table 3), those involving N1 the acceptor of the O–H···N hydrogen bond, and those involving N2, which is not a hydrogen-bond acceptor. As in compound (I), a single hydrogen bond (Table 4) links the components of (II), forming a C(12) chain (Bernstein et al., 1995) running parallel to the [001] direction (Fig. 6). In the corresponding DABCO adduct, the chains formed by the ionic components are linked into sheets by C—H···O hydrogen bonds (Zakaria et al., 2002).