Characterization of intra-framework and guest/host interactions in the AlPO₄-15 molecular sieve by charge-density analysis

The electron-density distribution of AlPO₄-15 has been determined using high-resolution single-crystal X-ray diffraction, and the topological properties of the charge density have been calculated using the `atoms in molecules' (AIM) theory. Analysis of the topological properties at the bond critical points has been used to characterize the interactions within the framework, and between the framework and the extra-framework species (ammonium ions and water molecules), and to define atomic properties, such as volume and net charges, uniquely. A comparison between procrystal and multipolar representations of the density was performed in order to explore to what extent the former representation is likely to reflect the interactions in the solid. Correlation with geometrical properties (P-O and Al-O bond lengths, and Al-O-P angle) is found for topological charges obtained from the multipolar model, but not for the results from the procrystal representation.

Computing details

Data collection: Nonius Kappa; cell refinement: HKL-2000 (Otwinowski et al.,2000); data reduction: DREAD (Blessing,1989); program(s) used to solve structure: NRCVAX (Gabe et al., 1989); program(s) used to refine structure: MoPro (Guillot et al., 2001).

(BDG2_2)

Crystal data

H3Al2O10P2·H4N·H2O	Z = 4
Mr = 314.98	F(000) = 640
Monoclinic, P21/n	Dx = 2.450 Mg m^−3
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.7107 Å
a = 9.556 (1) Å	µ = 0.76 mm^−1
b = 9.563 (1) Å	T = 115 K
c = 9.615 (1) Å	12-faced polyhedron, colourless
β = 103.58 (1)°	0.22 × 0.17 × 0.14 mm
V = 854.1 (2) Å^3

Data collection

Nonius KappaCCD diffractometer	8561 independent reflections
Radiation source: fine-focus sealed tube	8561 reflections with I > 0 u(I)
Graphite monochromator	Rint = 0.029
φ and ω scans	θmax = 49°, θmin = 3°
Absorption correction: integration Absorb, (DeTitta, 1985)	h = −19→19
Tmin = 0.89, Tmax = 0.93	k = −20→20
145662 measured reflections	l = −20→19

Refinement

Refinement on F	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.010	Weighting scheme based on measured s.u.'s
wR(F^2) = 0.007	(Δ/σ)max = 0.09
S = 1.65	Δρmax = 0.20 e Å^−3
4725 reflections	Δρmin = −0.20 e Å^−3
510 parameters	Extinction correction: Becker-Coppens, Becker & Coppens 1974
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 870
Secondary atom site location: difference Fourier map

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
P1	0.301122 (5)	0.532947 (5)	0.151339 (5)	0.00286 (1)
P2	0.794553 (5)	0.808911 (5)	0.136246 (5)	0.00280 (1)
Al1	0.613765 (7)	0.537615 (6)	0.127745 (6)	0.00313 (2)
Al2	0.393032 (7)	0.229762 (6)	0.184785 (6)	0.00327 (2)
O1	0.456755 (15)	0.586563 (15)	0.203054 (15)	0.00426 (3)
O2	0.192884 (15)	0.629269 (14)	0.193560 (15)	0.00485 (3)
O3	0.262779 (16)	0.520503 (15)	−0.013996 (14)	0.00426 (3)
O4	0.289272 (15)	0.386617 (14)	0.215291 (14)	0.00429 (3)
O5	0.954219 (15)	0.769346 (15)	0.165480 (15)	0.00485 (3)
O6	0.779190 (15)	0.950289 (14)	0.209248 (14)	0.00437 (3)
O7	0.708209 (16)	0.699363 (14)	0.196520 (15)	0.00483 (3)
O8	0.739606 (16)	0.824787 (15)	−0.024687 (14)	0.00476 (3)
O9	0.496655 (16)	0.364433 (15)	0.054527 (14)	0.00439 (3)
O10	0.500178 (16)	0.067277 (16)	0.146993 (16)	0.00683 (4)
O11	0.318871 (17)	0.856812 (16)	0.038092 (16)	0.00893 (4)
N	0.987422 (19)	0.308528 (19)	0.102664 (19)	0.00779 (4)
H1	0.5608 (4)	0.2984 (6)	0.0206 (4)	0.0084 (8)*
H2	0.4449 (5)	−0.0098 (5)	0.0992 (4)	0.0132 (10)*
H3	0.5961 (4)	0.0363 (4)	0.1889 (4)	0.0131 (10)*
H4	0.2668 (4)	0.8587 (5)	0.1118 (4)	0.0154 (10)*
H5	0.2650 (4)	0.9090 (4)	−0.0409 (4)	0.0145 (10)*
H6	0.9988 (4)	0.2780 (5)	0.0066 (4)	0.0132 (10)*
H7	0.8975 (4)	0.3652 (4)	0.0898 (4)	0.0144 (10)*
H8	0.9910 (4)	0.2261 (5)	0.1671 (4)	0.0134 (10)*
H9	1.0756 (4)	0.3634 (4)	0.1466 (4)	0.0134 (10)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P1	0.00269 (2)	0.00301 (2)	0.00288 (2)	−0.00020 (2)	0.00065 (2)	0.00016 (2)
P2	0.00267 (2)	0.00285 (2)	0.00263 (2)	−0.00014 (2)	0.00011 (2)	0.00001 (2)
Al1	0.00293 (3)	0.00345 (3)	0.00288 (3)	−0.00011 (2)	0.00044 (2)	−0.00014 (2)
Al2	0.00298 (3)	0.00359 (3)	0.00296 (3)	−0.00019 (2)	0.00015 (2)	−0.00008 (2)
O1	0.00301 (6)	0.00517 (6)	0.00459 (6)	−0.00106 (5)	0.00085 (5)	−0.00055 (5)
O2	0.00466 (6)	0.00528 (6)	0.00497 (6)	−0.00086 (5)	0.00184 (5)	0.00185 (5)
O3	0.00417 (6)	0.00584 (6)	0.00276 (5)	−0.00048 (4)	0.00078 (5)	0.00070 (5)
O4	0.00487 (6)	0.00320 (5)	0.00516 (6)	0.00068 (5)	0.00190 (5)	0.00029 (5)
O5	0.00297 (6)	0.00675 (6)	0.00437 (6)	−0.00015 (5)	−0.00006 (5)	0.00136 (5)
O6	0.00481 (6)	0.00359 (6)	0.00418 (6)	−0.00141 (4)	−0.00003 (5)	0.00027 (4)
O7	0.00580 (6)	0.00403 (6)	0.00469 (6)	−0.00013 (5)	0.00129 (5)	−0.00189 (5)
O8	0.00518 (6)	0.00585 (6)	0.00250 (5)	0.00006 (5)	−0.00058 (5)	−0.00055 (5)
O9	0.00413 (6)	0.00453 (6)	0.00448 (6)	−0.00044 (5)	0.00098 (5)	0.00059 (5)
O10	0.00491 (7)	0.00631 (6)	0.00889 (6)	−0.00198 (5)	0.00084 (5)	0.00096 (5)
O11	0.01051 (7)	0.00863 (7)	0.00823 (7)	0.00091 (5)	0.00336 (6)	−0.00036 (5)
N	0.00693 (8)	0.00947 (7)	0.00683 (7)	0.00152 (6)	0.00134 (6)	0.00044 (6)

Geometric parameters (Å, º)

P1—O1	1.5410 (2)	Al2—O4	1.8590 (2)
P1—O2	1.5101 (2)	Al2—O5	1.8330 (2)
P1—O3	1.5498 (2)	Al2—O8	1.8254 (2)
P1—O4	1.5433 (2)	Al2—O9	2.1886 (3)
P2—O5	1.5326 (2)	Al2—O10	1.9415 (3)
P2—O6	1.5461 (2)	O9—H1	0.987 (5)
P2—O7	1.5293 (2)	O10—H2	0.959 (5)
P2—O8	1.5204 (2)	O10—H3	0.958 (4)
Al1—O1	1.8721 (3)	O11—H4	0.957 (4)
Al1—O3	1.8716 (3)	O11—H5	0.953 (4)
Al1—O6	1.8567 (2)	N—H6	0.999 (4)
Al1—O7	1.8342 (2)	N—H7	0.999 (4)
Al1—O9	2.0300 (3)	N—H8	0.998 (4)
Al1—O9	2.0479 (3)	N—H9	0.998 (4)
Al2—O2	1.8485 (2)
O1—P1—O2	112.36 (1)	O9—Al2—O8	90.20 (1)
O1—P1—O3	109.53 (1)	O10—Al2—O2	91.97 (1)
O1—P1—O4	109.19 (1)	O2—Al2—O8	93.52 (1)
O2—P1—O3	108.10 (1)	O5—Al2—O2	90.03 (1)
O2—P1—O4	109.09 (1)	O5—Al2—O4	93.74 (1)
O3—P1—O4	108.50 (1)	O5—Al2—O10	87.40 (1)
O5—P2—O6	109.22 (1)	O8—Al2—O5	171.34 (1)
O5—P2—O7	111.34 (1)	O5—Al2—O9	86.79 (1)
O5—P2—O8	107.60 (1)	O10—Al2—O8	84.59 (1)
O6—P2—O7	108.05 (1)	P1—O1—Al1	126.33 (1)
O6—P2—O8	109.14 (1)	P1—O3—Al1	126.34 (1)
O7—P2—O8	111.47 (1)	P2—O5—Al2	140.35 (1)
O1—Al1—O7	91.20 (1)	P2—O7—Al1	134.80 (1)
O1—Al1—O9	84.92 (1)	P1—O2—Al2	157.12 (1)
O1—Al1—O3	166.58 (1)	P1—O4—Al2	125.24 (1)
O1—Al1—O9	85.29 (1)	P2—O6—Al1	133.18 (1)
O7—Al1—O9	176.02 (1)	P2—O8—Al2	146.64 (1)
O7—Al1—O3	97.86 (1)	Al1—O9—Al1	93.15 (1)
O7—Al1—O9	91.94 (1)	Al1—O9—Al2	124.63 (1)
O9—Al1—O3	85.81 (1)	Al2—O9—Al1	123.19 (1)
O9—Al1—O9	86.85 (1)	Al1—O9—H1	107.6 (3)
O3—Al1—O9	84.52 (1)	Al2—O9—H1	102.2 (3)
O7—Al1—O6	87.02 (1)	H1—O9—Al1	104.2 (2)
O6—Al1—O3	93.54 (1)	Al2—O10—H2	116.7 (3)
O6—Al1—O1	96.82 (1)	Al2—O10—H3	131.6 (2)
O6—Al1—O9	94.32 (1)	H2—O10—H3	109.2 (4)
O6—Al1—O9	177.66 (1)	H4—O11—H5	107.6 (3)
O4—Al2—O9	86.86 (1)	H6—N—H7	108.7 (3)
O4—Al2—O10	178.32 (1)	H6—N—H8	110.4 (4)
O4—Al2—O2	89.26 (1)	H6—N—H9	106.3 (3)
O4—Al2—O8	94.20 (1)	H7—N—H8	114.1 (3)
O9—Al2—O10	91.98 (1)	H7—N—H9	112.5 (3)
O9—Al2—O2	174.81 (1)	H8—N—H9	104.5 (3)