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The dimeric title coordination compound, [Al
2(C
4H
9)
2Cl
2(C
3H
8N)
2], comprises tetrahedral Al atoms each bonded to two N atoms of the amide ligands, one C atom of the
tert-butyl group and one Cl atom. The Al atoms are bridged by amide moieties, creating a planar four-membered Al
2N
2 ring, which may be considered as the main structural feature. A twofold rotation axis passes through the centre of the ring. The Al—N bond distance are 1.943 (4) and 1.962 (4) Å. Pseudosymmetry in space group
P4
2/
nmc was considered but the space group
P2
1c was confirmed by the structure solution and refinement.
Supporting information
CCDC reference: 252755
Key indicators
- Single-crystal X-ray study
- T = 213 K
- Mean (C-C) = 0.007 Å
- R factor = 0.060
- wR factor = 0.124
- Data-to-parameter ratio = 23.5
checkCIF/PLATON results
No syntax errors found
Alert level B
PLAT111_ALERT_2_B ADDSYM Detects (Pseudo) Centre of Symmetry ..... 90 PerFit
| Author Response: See PLAT_113.
|
PLAT112_ALERT_2_B ADDSYM Detects Additional (Pseudo) Symm. Elem... 4
PLAT112_ALERT_2_B ADDSYM Detects Additional (Pseudo) Symm. Elem... m
PLAT112_ALERT_2_B ADDSYM Detects Additional (Pseudo) Symm. Elem... m
PLAT113_ALERT_2_B ADDSYM Suggests Possible Pseudo/New Spacegroup . P42/nmc
| Author Response: Refinement in suggested new space group was checked and proofed
to be unstable.
|
Alert level C
STRVA01_ALERT_4_C Flack test results are ambiguous.
From the CIF: _refine_ls_abs_structure_Flack 0.500
From the CIF: _refine_ls_abs_structure_Flack_su 0.200
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero ....... 0.50
PLAT141_ALERT_4_C su on a - Axis Small or Missing (x 100000) ..... 10 Ang.
PLAT242_ALERT_2_C Check Low U(eq) as Compared to Neighbors for C1
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 7
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) . 1.20 Ratio
Alert level G
REFLT03_ALERT_4_G 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.
From the CIF: _diffrn_reflns_theta_max 27.22
From the CIF: _reflns_number_total 2162
Count of symmetry unique reflns 1330
Completeness (_total/calc) 162.56%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 832
Fraction of Friedel pairs measured 0.626
Are heavy atom types Z>Si present yes
0 ALERT level A = In general: serious problem
5 ALERT level B = Potentially serious problem
6 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
7 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
4 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003).
Bis(µ-
N-methylethylamido)bis[
tert-butylchloroaluminium]
top
Crystal data top
[Al2(C4H9)2Cl2(C3H8N)2] | Dx = 1.130 Mg m−3 |
Mr = 355.29 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, P421c | Cell parameters from 8923 reflections |
Hall symbol: P-42n | θ = 2–25° |
a = 12.0110 (1) Å | µ = 0.39 mm−1 |
c = 14.4768 (3) Å | T = 213 K |
V = 2088.48 (5) Å3 | Block, colourless |
Z = 4 | 0.40 × 0.30 × 0.20 mm |
F(000) = 768 | |
Data collection top
BRUKER smart CCD diffractometer | 2162 independent reflections |
Radiation source: fine-focus sealed tube | 1693 reflections with i > 2Σ(I) |
Graphite monochromator | Rint = 0.094 |
ω scans | θmax = 27.2°, θmin = 2.2° |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | h = −6→14 |
Tmin = 0.860, Tmax = 0.926 | k = −14→14 |
8923 measured reflections | l = −18→15 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.060 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.124 | w = 1/[σ2(Fo2) + (0.0324P)2 + 1.7272P] where P = (Fo2 + 2Fc2)/3 |
S = 1.17 | (Δ/σ)max < 0.001 |
2162 reflections | Δρmax = 0.35 e Å−3 |
92 parameters | Δρmin = −0.37 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 832 Friedel reflections [CHECK] |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.5 (2) |
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Al1 | 0.38453 (7) | −0.00653 (12) | 0.10112 (6) | 0.0302 (2) | |
Cl1 | 0.33940 (8) | −0.00943 (15) | −0.04225 (6) | 0.0572 (3) | |
N1 | 0.4947 (3) | 0.1123 (2) | 0.11765 (15) | 0.0339 (6) | |
C1 | 0.2489 (3) | −0.0085 (5) | 0.1792 (2) | 0.0427 (9) | |
C2 | 0.1823 (4) | 0.0962 (5) | 0.1546 (4) | 0.0668 (18) | |
H2A | 0.1725 | 0.1001 | 0.0882 | 0.077 (3)* | |
H2B | 0.2222 | 0.1616 | 0.1757 | 0.077 (3)* | |
H2C | 0.1100 | 0.0932 | 0.1843 | 0.077 (3)* | |
C3 | 0.2624 (3) | −0.0111 (7) | 0.2842 (2) | 0.0689 (15) | |
H3A | 0.3040 | −0.0769 | 0.3019 | 0.077 (3)* | |
H3B | 0.1896 | −0.0128 | 0.3131 | 0.077 (3)* | |
H3C | 0.3022 | 0.0549 | 0.3043 | 0.077 (3)* | |
C4 | 0.1795 (5) | −0.1105 (6) | 0.1513 (5) | 0.0722 (19) | |
H4A | 0.2203 | −0.1778 | 0.1661 | 0.077 (3)* | |
H4B | 0.1649 | −0.1081 | 0.0854 | 0.077 (3)* | |
H4C | 0.1095 | −0.1099 | 0.1847 | 0.077 (3)* | |
C5 | 0.4924 (5) | 0.1571 (3) | 0.2144 (2) | 0.0487 (9) | |
H5A | 0.5002 | 0.0961 | 0.2578 | 0.077 (3)* | |
H5B | 0.4221 | 0.1947 | 0.2251 | 0.077 (3)* | |
H5C | 0.5532 | 0.2092 | 0.2227 | 0.077 (3)* | |
C6 | 0.4827 (4) | 0.2076 (3) | 0.0511 (3) | 0.0541 (12) | |
H6A | 0.4771 | 0.1772 | −0.0116 | 0.077 (3)* | |
H6B | 0.4127 | 0.2463 | 0.0645 | 0.077 (3)* | |
C7 | 0.5751 (5) | 0.2906 (4) | 0.0532 (4) | 0.0843 (18) | |
H7A | 0.5603 | 0.3490 | 0.0086 | 0.077 (3)* | |
H7B | 0.6447 | 0.2540 | 0.0378 | 0.077 (3)* | |
H7C | 0.5805 | 0.3227 | 0.1145 | 0.077 (3)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Al1 | 0.0287 (4) | 0.0368 (5) | 0.0252 (4) | −0.0013 (6) | −0.0020 (4) | 0.0004 (7) |
Cl1 | 0.0565 (6) | 0.0843 (8) | 0.0307 (4) | −0.0047 (8) | −0.0116 (4) | −0.0018 (8) |
N1 | 0.0397 (15) | 0.0310 (12) | 0.0309 (12) | 0.003 (2) | 0.000 (2) | −0.0009 (10) |
C1 | 0.0306 (16) | 0.057 (2) | 0.0401 (17) | 0.000 (2) | 0.0043 (14) | 0.005 (3) |
C2 | 0.046 (3) | 0.083 (4) | 0.072 (5) | 0.020 (3) | 0.010 (3) | 0.007 (3) |
C3 | 0.049 (2) | 0.116 (4) | 0.042 (2) | 0.003 (4) | 0.0167 (18) | 0.011 (4) |
C4 | 0.048 (3) | 0.086 (4) | 0.083 (5) | −0.018 (3) | 0.016 (3) | 0.001 (4) |
C5 | 0.052 (2) | 0.048 (2) | 0.0461 (18) | 0.006 (3) | −0.007 (3) | −0.0208 (16) |
C6 | 0.061 (3) | 0.038 (2) | 0.064 (2) | −0.002 (2) | −0.008 (3) | 0.0164 (19) |
C7 | 0.091 (4) | 0.059 (3) | 0.103 (5) | −0.020 (3) | −0.014 (4) | 0.029 (3) |
Geometric parameters (Å, º) top
Al1—N1i | 1.943 (4) | C3—H3B | 0.9700 |
Al1—N1 | 1.962 (4) | C3—H3C | 0.9700 |
Al1—C1 | 1.983 (3) | C4—H4A | 0.9700 |
Al1—Cl1 | 2.1455 (12) | C4—H4B | 0.9700 |
Al1—Al1i | 2.7782 (18) | C4—H4C | 0.9700 |
N1—C5 | 1.500 (4) | C5—H5A | 0.9700 |
N1—C6 | 1.502 (4) | C5—H5B | 0.9700 |
N1—Al1i | 1.943 (4) | C5—H5C | 0.9700 |
C1—C3 | 1.530 (5) | C6—C7 | 1.493 (7) |
C1—C2 | 1.533 (7) | C6—H6A | 0.9800 |
C1—C4 | 1.535 (8) | C6—H6B | 0.9800 |
C2—H2A | 0.9700 | C7—H7A | 0.9700 |
C2—H2B | 0.9700 | C7—H7B | 0.9700 |
C2—H2C | 0.9700 | C7—H7C | 0.9700 |
C3—H3A | 0.9700 | | |
| | | |
N1i—Al1—N1 | 87.56 (12) | C1—C3—H3B | 109.5 |
N1i—Al1—C1 | 122.36 (18) | H3A—C3—H3B | 109.5 |
N1—Al1—C1 | 119.58 (19) | C1—C3—H3C | 109.5 |
N1i—Al1—Cl1 | 107.28 (10) | H3A—C3—H3C | 109.5 |
N1—Al1—Cl1 | 107.48 (10) | H3B—C3—H3C | 109.5 |
C1—Al1—Cl1 | 110.08 (11) | C1—C4—H4A | 109.5 |
N1i—Al1—Al1i | 44.91 (10) | C1—C4—H4B | 109.5 |
N1—Al1—Al1i | 44.37 (11) | H4A—C4—H4B | 109.5 |
C1—Al1—Al1i | 145.19 (10) | C1—C4—H4C | 109.5 |
Cl1—Al1—Al1i | 104.67 (4) | H4A—C4—H4C | 109.5 |
C5—N1—C6 | 108.9 (3) | H4B—C4—H4C | 109.5 |
C5—N1—Al1i | 111.3 (3) | N1—C5—H5A | 109.5 |
C6—N1—Al1i | 119.4 (3) | N1—C5—H5B | 109.5 |
C5—N1—Al1 | 111.2 (3) | H5A—C5—H5B | 109.5 |
C6—N1—Al1 | 114.3 (3) | N1—C5—H5C | 109.5 |
Al1i—N1—Al1 | 90.71 (11) | H5A—C5—H5C | 109.5 |
C3—C1—C2 | 107.6 (5) | H5B—C5—H5C | 109.5 |
C3—C1—C4 | 107.7 (5) | C7—C6—N1 | 115.1 (4) |
C2—C1—C4 | 108.1 (3) | C7—C6—H6A | 108.5 |
C3—C1—Al1 | 118.6 (2) | N1—C6—H6A | 108.5 |
C2—C1—Al1 | 106.7 (3) | C7—C6—H6B | 108.5 |
C4—C1—Al1 | 107.8 (3) | N1—C6—H6B | 108.5 |
C1—C2—H2A | 109.5 | H6A—C6—H6B | 107.5 |
C1—C2—H2B | 109.5 | C6—C7—H7A | 109.5 |
H2A—C2—H2B | 109.5 | C6—C7—H7B | 109.5 |
C1—C2—H2C | 109.5 | H7A—C7—H7B | 109.5 |
H2A—C2—H2C | 109.5 | C6—C7—H7C | 109.5 |
H2B—C2—H2C | 109.5 | H7A—C7—H7C | 109.5 |
C1—C3—H3A | 109.5 | H7B—C7—H7C | 109.5 |
| | | |
N1i—Al1—N1—C5 | −99.2 (3) | Cl1—Al1—C1—C3 | 177.8 (5) |
C1—Al1—N1—C5 | 27.1 (3) | Al1i—Al1—C1—C3 | −5.6 (8) |
Cl1—Al1—N1—C5 | 153.4 (3) | N1i—Al1—C1—C2 | 172.1 (3) |
Al1i—Al1—N1—C5 | −113.3 (3) | N1—Al1—C1—C2 | 64.5 (3) |
N1i—Al1—N1—C6 | 137.0 (3) | Cl1—Al1—C1—C2 | −60.6 (4) |
C1—Al1—N1—C6 | −96.7 (3) | Al1i—Al1—C1—C2 | 115.9 (3) |
Cl1—Al1—N1—C6 | 29.7 (3) | N1i—Al1—C1—C4 | −72.0 (4) |
Al1i—Al1—N1—C6 | 123.0 (3) | N1—Al1—C1—C4 | −179.6 (3) |
N1i—Al1—N1—Al1i | 14.05 (14) | Cl1—Al1—C1—C4 | 55.3 (4) |
C1—Al1—N1—Al1i | 140.34 (16) | Al1i—Al1—C1—C4 | −128.2 (4) |
Cl1—Al1—N1—Al1i | −93.31 (10) | C5—N1—C6—C7 | 63.6 (6) |
N1i—Al1—C1—C3 | 50.5 (6) | Al1i—N1—C6—C7 | −65.8 (5) |
N1—Al1—C1—C3 | −57.1 (6) | Al1—N1—C6—C7 | −171.4 (4) |
Symmetry code: (i) −x+1, −y, z. |
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