A three-dimensional open-framework zinc arsenate, (C₄H₁₂N₂)₂[Zn₇(AsO₄)₆­(H₂O)₂]

The title compound, dipiperazinium heptazinc hexakis(arsen­ate) dihydrate, is built from vertex-sharing AsO₄ tetrahedra, ZnO₄ tetrahedra and ZnO₅ trigonal bipyramids. The connectivity between these polyhedra give rise to an open framework with eight-ring channels along the crystallographic [001] and [011] directions. The piperazinium cations are located within these channels.

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1994); program(s) used to refine structure: SHELXTL; software used to prepare material for publication: SHELXTL.

(I)

Crystal data

(C4H12N2)2[Zn7(AsO4)6(H2O)2]	F(000) = 2880
Mr = 1503.46	Dx = 3.179 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 16.5880 (14) Å	Cell parameters from 3669 reflections
b = 8.3559 (7) Å	θ = 3–27.5°
c = 23.4129 (18) Å	µ = 11.64 mm^−1
β = 104.564 (4)°	T = 150 K
V = 3140.9 (4) Å^3	Plate, colourless
Z = 4	0.4 × 0.1 × 0.05 mm

Data collection

Siemens SMART CCD diffractometer	3602 independent reflections
Radiation source: fine-focus sealed tube	2639 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.079
Detector resolution: 8.3 pixels mm^-1	θmax = 27.5°, θmin = 2.5°
sets of exposures each taken over 0.6° ω rotation scans	h = −21→21
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	k = −10→10
Tmin = 0.26, Tmax = 0.55	l = −30→30
17378 measured reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.032	w = 1/[σ^2(Fo^2) + (0.0275P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.065	(Δ/σ)max = 0.001
S = 0.95	Δρmax = 0.87 e Å^−3
3602 reflections	Δρmin = −0.92 e Å^−3
273 parameters

Special details

Experimental. The data collection nominally covered a hemisphere of reciprocal space by a combination of five sets of exposures at a 5.0 cm crystal-to-detector distance.

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 (Ų)

	x	y	z	Uiso*/Ueq
As1	0.26918 (3)	0.50999 (7)	0.54802 (2)	0.00799 (12)
As2	0.05209 (3)	0.28361 (7)	0.13313 (2)	0.00828 (12)
As3	0.17838 (3)	0.50461 (7)	0.30936 (2)	0.00834 (12)
Zn1	0.30098 (4)	0.65114 (8)	0.42636 (3)	0.00896 (13)
Zn2	−0.14715 (4)	0.35305 (8)	0.07431 (3)	0.00908 (14)
Zn3	0.24056 (4)	0.38125 (8)	0.19269 (3)	0.00976 (14)
Zn4	0.0000	0.30442 (11)	0.2500	0.00970 (19)
O1	0.3245 (2)	0.3634 (5)	0.58939 (16)	0.0159 (8)
O2	0.1798 (2)	0.4451 (5)	0.50431 (16)	0.0161 (9)
O3	0.2507 (2)	0.6421 (5)	0.59762 (16)	0.0115 (8)
O4	0.3292 (2)	0.6040 (5)	0.50954 (15)	0.0123 (8)
O5	0.0935 (2)	0.1434 (5)	0.09622 (16)	0.0121 (8)
O6	0.0216 (2)	0.1793 (4)	0.18557 (16)	0.0119 (8)
O7	−0.0273 (2)	0.3795 (5)	0.08565 (16)	0.0116 (8)
O8	0.1224 (2)	0.4234 (4)	0.16244 (16)	0.0115 (8)
O9	0.2159 (2)	0.4929 (5)	0.38491 (15)	0.0107 (7)
O10	0.1931 (3)	0.6885 (5)	0.28760 (16)	0.0158 (8)
O11	0.0786 (2)	0.4587 (5)	0.29750 (17)	0.0182 (9)
O12	0.2335 (2)	0.3720 (5)	0.28051 (15)	0.0124 (8)
OW	0.3168 (3)	0.5693 (5)	0.20120 (17)	0.0138 (8)
N1	0.4585 (3)	0.2146 (6)	0.0799 (2)	0.0162 (10)
N2	0.6076 (3)	0.3471 (6)	0.1519 (2)	0.0136 (10)
C1	0.5411 (4)	0.2887 (8)	0.1785 (3)	0.0139 (12)
C2	0.4585 (4)	0.3062 (7)	0.1344 (3)	0.0152 (12)
C3	0.5262 (4)	0.7284 (8)	0.5522 (3)	0.0170 (12)
C4	0.6086 (4)	0.2555 (7)	0.0968 (3)	0.0155 (12)
H1	0.413 (4)	0.224 (8)	0.055 (3)	0.020*
H2	0.470 (4)	0.110 (9)	0.092 (3)	0.020*
H3	0.602 (4)	0.438 (9)	0.143 (3)	0.020*
H4	0.663 (4)	0.355 (8)	0.173 (3)	0.020*
H5	0.555 (4)	0.186 (9)	0.196 (3)	0.020*
H6	0.543 (4)	0.345 (9)	0.209 (3)	0.020*
H7	0.412 (4)	0.267 (8)	0.154 (3)	0.020*
H8	0.448 (4)	0.417 (9)	0.126 (3)	0.020*
H9	0.514 (4)	0.624 (9)	0.543 (3)	0.020*
H10	0.526 (4)	0.787 (8)	0.522 (3)	0.020*
H11	0.621 (4)	0.158 (9)	0.107 (3)	0.020*
H12	0.648 (4)	0.295 (8)	0.084 (3)	0.020*
H13	0.304 (4)	0.659 (9)	0.218 (3)	0.020*
H14	0.322 (4)	0.589 (9)	0.171 (3)	0.020*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
As1	0.0091 (2)	0.0074 (3)	0.0073 (2)	−0.0003 (2)	0.00190 (18)	−0.0005 (2)
As2	0.0080 (2)	0.0080 (3)	0.0085 (3)	0.0005 (2)	0.00160 (19)	−0.0002 (2)
As3	0.0090 (2)	0.0080 (3)	0.0082 (2)	−0.0012 (2)	0.00239 (18)	−0.0004 (2)
Zn1	0.0100 (3)	0.0085 (3)	0.0086 (3)	0.0002 (2)	0.0029 (2)	0.0005 (2)
Zn2	0.0081 (3)	0.0085 (3)	0.0105 (3)	0.0003 (2)	0.0023 (2)	0.0009 (2)
Zn3	0.0094 (3)	0.0088 (3)	0.0106 (3)	0.0007 (2)	0.0016 (2)	0.0002 (2)
Zn4	0.0101 (4)	0.0101 (4)	0.0087 (4)	0.000	0.0020 (3)	0.000
O1	0.027 (2)	0.008 (2)	0.014 (2)	0.0042 (17)	0.0050 (17)	0.0036 (16)
O2	0.0098 (18)	0.028 (2)	0.0092 (18)	−0.0066 (17)	0.0003 (14)	−0.0074 (17)
O3	0.018 (2)	0.0077 (18)	0.0081 (18)	0.0043 (16)	0.0024 (15)	0.0036 (15)
O4	0.0118 (18)	0.017 (2)	0.0078 (18)	−0.0038 (16)	0.0027 (14)	0.0020 (16)
O5	0.0117 (18)	0.0111 (19)	0.0150 (19)	−0.0007 (16)	0.0063 (15)	−0.0025 (16)
O6	0.0170 (19)	0.0077 (19)	0.0117 (19)	0.0024 (16)	0.0047 (15)	0.0008 (15)
O7	0.0083 (17)	0.014 (2)	0.0119 (19)	0.0008 (16)	0.0017 (14)	0.0038 (16)
O8	0.0103 (18)	0.0096 (19)	0.0125 (19)	−0.0002 (15)	−0.0010 (14)	−0.0019 (16)
O9	0.0150 (18)	0.0092 (19)	0.0073 (17)	−0.0031 (16)	0.0020 (14)	−0.0032 (15)
O10	0.025 (2)	0.012 (2)	0.0104 (19)	−0.0050 (17)	0.0047 (16)	0.0011 (16)
O11	0.0122 (19)	0.023 (2)	0.022 (2)	−0.0075 (17)	0.0084 (16)	−0.0101 (18)
O12	0.0143 (19)	0.016 (2)	0.0082 (18)	0.0031 (16)	0.0046 (15)	−0.0003 (16)
OW	0.024 (2)	0.010 (2)	0.009 (2)	−0.0018 (17)	0.0063 (17)	−0.0010 (16)
N1	0.011 (2)	0.012 (2)	0.021 (3)	−0.001 (2)	−0.003 (2)	0.004 (2)
N2	0.015 (2)	0.008 (2)	0.018 (3)	−0.003 (2)	0.0044 (19)	−0.001 (2)
C1	0.014 (3)	0.014 (3)	0.014 (3)	0.000 (2)	0.005 (2)	0.005 (2)
C2	0.014 (3)	0.014 (3)	0.018 (3)	−0.002 (2)	0.003 (2)	0.000 (3)
C3	0.023 (3)	0.012 (3)	0.017 (3)	−0.004 (3)	0.007 (2)	0.000 (3)
C4	0.018 (3)	0.013 (3)	0.017 (3)	−0.001 (2)	0.007 (2)	−0.001 (2)

Geometric parameters (Å, º)

As1—O2	1.667 (4)	O1—Zn2^vii	1.924 (4)
As1—O1	1.683 (4)	O2—Zn2^iv	1.942 (4)
As1—O3	1.686 (4)	O3—Zn1^i	1.947 (4)
As1—O4	1.695 (4)	O3—Zn3^viii	2.282 (4)
As2—O8	1.671 (4)	O5—Zn1^v	1.953 (4)
As2—O6	1.684 (4)	O9—Zn2^iv	2.031 (4)
As2—O7	1.696 (4)	O10—Zn3^ii	1.940 (4)
As2—O5	1.699 (4)	OW—H13	0.89 (7)
As3—O11	1.653 (4)	OW—H14	0.74 (7)
As3—O10	1.656 (4)	N1—C2	1.488 (8)
As3—O12	1.682 (4)	N1—C3^vi	1.507 (8)
As3—O9	1.724 (3)	N1—H1	0.83 (7)
Zn1—O4	1.926 (4)	N1—H2	0.93 (7)
Zn1—O3^i	1.947 (4)	N2—C1	1.480 (7)
Zn1—O5^ii	1.953 (4)	N2—C4	1.503 (8)
Zn1—O9	1.998 (4)	N2—H3	0.79 (7)
Zn2—O1^iii	1.924 (4)	N2—H4	0.93 (7)
Zn2—O2^iv	1.942 (4)	C1—C2	1.502 (8)
Zn2—O7	1.951 (4)	C1—H5	0.95 (7)
Zn2—O9^iv	2.031 (4)	C1—H6	0.85 (7)
Zn3—O10^v	1.940 (4)	C2—H7	1.04 (6)
Zn3—O8	1.942 (4)	C2—H8	0.96 (7)
Zn3—OW	1.995 (4)	C3—C4^viii	1.504 (8)
Zn3—O12	2.090 (4)	C3—N1^viii	1.507 (8)
Zn3—O3^vi	2.282 (4)	C3—H9	0.91 (7)
Zn4—O6	1.941 (4)	C3—H10	0.85 (7)
Zn4—O6^iv	1.941 (4)	C4—C3^vi	1.504 (8)
Zn4—O11	1.967 (4)	C4—H11	0.86 (7)
Zn4—O11^iv	1.967 (4)	C4—H12	0.85 (7)
O2—As1—O1	112.9 (2)	As1—O4—Zn1	127.3 (2)
O2—As1—O3	110.37 (18)	As2—O5—Zn1^v	128.3 (2)
O1—As1—O3	104.32 (18)	As2—O6—Zn4	115.9 (2)
O2—As1—O4	112.07 (18)	As2—O7—Zn2	129.2 (2)
O1—As1—O4	109.60 (19)	As2—O8—Zn3	124.0 (2)
O3—As1—O4	107.21 (19)	As3—O9—Zn1	119.3 (2)
O8—As2—O6	111.64 (18)	As3—O9—Zn2^iv	114.48 (18)
O8—As2—O7	106.60 (19)	Zn1—O9—Zn2^iv	124.33 (17)
O6—As2—O7	113.34 (18)	As3—O10—Zn3^ii	144.7 (2)
O8—As2—O5	111.18 (18)	As3—O11—Zn4	137.8 (2)
O6—As2—O5	104.36 (18)	As3—O12—Zn3	122.8 (2)
O7—As2—O5	109.79 (18)	Zn3—OW—H13	119 (4)
O11—As3—O10	112.5 (2)	Zn3—OW—H14	108 (6)
O11—As3—O12	113.7 (2)	H13—OW—H14	108 (7)
O10—As3—O12	110.5 (2)	C2—N1—C3^vi	111.5 (5)
O11—As3—O9	104.30 (18)	C2—N1—H1	111 (5)
O10—As3—O9	108.97 (18)	C3^vi—N1—H1	107 (5)
O12—As3—O9	106.39 (18)	C2—N1—H2	106 (4)
O4—Zn1—O3^i	116.76 (16)	C3^vi—N1—H2	108 (4)
O4—Zn1—O5^ii	105.09 (15)	H1—N1—H2	113 (6)
O3^i—Zn1—O5^ii	108.09 (16)	C1—N2—C4	111.4 (5)
O4—Zn1—O9	108.56 (16)	C1—N2—H3	112 (5)
O3^i—Zn1—O9	103.96 (16)	C4—N2—H3	107 (5)
O5^ii—Zn1—O9	114.75 (16)	C1—N2—H4	123 (4)
O1^iii—Zn2—O2^iv	121.56 (17)	C4—N2—H4	105 (4)
O1^iii—Zn2—O7	111.70 (17)	H3—N2—H4	96 (6)
O2^iv—Zn2—O7	96.64 (15)	N2—C1—C2	108.9 (5)
O1^iii—Zn2—O9^iv	105.21 (16)	N2—C1—H5	111 (4)
O2^iv—Zn2—O9^iv	99.33 (15)	C2—C1—H5	118 (4)
O7—Zn2—O9^iv	122.97 (16)	N2—C1—H6	107 (5)
O10^v—Zn3—O8	134.22 (17)	C2—C1—H6	111 (4)
O10^v—Zn3—OW	108.83 (17)	H5—C1—H6	100 (6)
O8—Zn3—OW	116.77 (17)	N1—C2—C1	110.1 (5)
O10^v—Zn3—O12	84.50 (15)	N1—C2—H7	112 (4)
O8—Zn3—O12	93.67 (15)	C1—C2—H7	108 (3)
OW—Zn3—O12	97.00 (16)	N1—C2—H8	111 (4)
O10^v—Zn3—O3^vi	89.12 (15)	C1—C2—H8	109 (4)
O8—Zn3—O3^vi	88.56 (14)	H7—C2—H8	106 (5)
OW—Zn3—O3^vi	87.97 (15)	C4^viii—C3—N1^viii	108.6 (5)
O12—Zn3—O3^vi	172.91 (15)	C4^viii—C3—H9	111 (4)
O6—Zn4—O6^iv	114.8 (2)	N1^viii—C3—H9	105 (4)
O6—Zn4—O11	124.52 (16)	C4^viii—C3—H10	109 (4)
O6^iv—Zn4—O11	97.99 (16)	N1^viii—C3—H10	109 (4)
O6—Zn4—O11^iv	97.99 (16)	H9—C3—H10	114 (6)
O6^iv—Zn4—O11^iv	124.52 (16)	N2—C4—C3^vi	110.2 (5)
O11—Zn4—O11^iv	98.1 (3)	N2—C4—H11	107 (4)
As1—O1—Zn2^vii	134.5 (2)	C3^vi—C4—H11	113 (4)
As1—O2—Zn2^iv	134.7 (2)	N2—C4—H12	106 (4)
As1—O3—Zn1^i	121.7 (2)	C3^vi—C4—H12	112 (4)
As1—O3—Zn3^viii	133.4 (2)	H11—C4—H12	109 (6)
Zn1^i—O3—Zn3^viii	102.84 (16)
O2—As1—O1—Zn2^vii	44.3 (4)	O10^v—Zn3—O8—As2	−13.6 (4)
O3—As1—O1—Zn2^vii	164.1 (3)	OW—Zn3—O8—As2	160.8 (2)
O4—As1—O1—Zn2^vii	−81.4 (3)	O12—Zn3—O8—As2	−99.5 (3)
O1—As1—O2—Zn2^iv	−87.0 (4)	O3^vi—Zn3—O8—As2	73.8 (2)
O3—As1—O2—Zn2^iv	156.7 (3)	O11—As3—O9—Zn1	−142.4 (2)
O4—As1—O2—Zn2^iv	37.3 (4)	O10—As3—O9—Zn1	−22.0 (3)
O2—As1—O3—Zn1^i	−65.5 (3)	O12—As3—O9—Zn1	97.1 (2)
O1—As1—O3—Zn1^i	173.0 (2)	O11—As3—O9—Zn2^iv	22.7 (3)
O4—As1—O3—Zn1^i	56.8 (3)	O10—As3—O9—Zn2^iv	143.0 (2)
O2—As1—O3—Zn3^viii	95.0 (3)	O12—As3—O9—Zn2^iv	−97.8 (2)
O1—As1—O3—Zn3^viii	−26.5 (3)	O4—Zn1—O9—As3	−179.9 (2)
O4—As1—O3—Zn3^viii	−142.7 (3)	O3^i—Zn1—O9—As3	55.2 (2)
O2—As1—O4—Zn1	4.4 (3)	O5^ii—Zn1—O9—As3	−62.7 (3)
O1—As1—O4—Zn1	130.5 (3)	O4—Zn1—O9—Zn2^iv	16.7 (3)
O3—As1—O4—Zn1	−116.9 (3)	O3^i—Zn1—O9—Zn2^iv	−108.3 (2)
O3^i—Zn1—O4—As1	91.4 (3)	O5^ii—Zn1—O9—Zn2^iv	133.9 (2)
O5^ii—Zn1—O4—As1	−148.9 (3)	O11—As3—O10—Zn3^ii	139.2 (4)
O9—Zn1—O4—As1	−25.7 (3)	O12—As3—O10—Zn3^ii	−92.5 (4)
O8—As2—O5—Zn1^v	−12.1 (3)	O9—As3—O10—Zn3^ii	24.0 (5)
O6—As2—O5—Zn1^v	−132.6 (3)	O10—As3—O11—Zn4	116.7 (4)
O7—As2—O5—Zn1^v	105.6 (3)	O12—As3—O11—Zn4	−9.9 (4)
O8—As2—O6—Zn4	43.1 (3)	O9—As3—O11—Zn4	−125.4 (4)
O7—As2—O6—Zn4	−77.2 (2)	O6—Zn4—O11—As3	−14.3 (5)
O5—As2—O6—Zn4	163.3 (2)	O6^iv—Zn4—O11—As3	113.4 (4)
O6^iv—Zn4—O6—As2	−172.7 (3)	O11^iv—Zn4—O11—As3	−119.9 (4)
O11—Zn4—O6—As2	−52.4 (3)	O11—As3—O12—Zn3	84.6 (3)
O11^iv—Zn4—O6—As2	53.2 (2)	O10—As3—O12—Zn3	−43.0 (3)
O8—As2—O7—Zn2	−136.3 (3)	O9—As3—O12—Zn3	−161.2 (2)
O6—As2—O7—Zn2	−13.0 (3)	O10^v—Zn3—O12—As3	−177.6 (3)
O5—As2—O7—Zn2	103.2 (3)	O8—Zn3—O12—As3	−43.5 (3)
O1^iii—Zn2—O7—As2	−31.6 (3)	OW—Zn3—O12—As3	74.0 (3)
O2^iv—Zn2—O7—As2	−159.5 (3)	O3^vi—Zn3—O12—As3	−151.7 (10)
O9^iv—Zn2—O7—As2	94.8 (3)	C4—N2—C1—C2	−59.0 (6)
O6—As2—O8—Zn3	82.2 (3)	C3^vi—N1—C2—C1	−59.2 (6)
O7—As2—O8—Zn3	−153.6 (2)	N2—C1—C2—N1	58.5 (6)
O5—As2—O8—Zn3	−33.9 (3)	C1—N2—C4—C3^vi	59.2 (6)

Symmetry codes: (i) −x+1/2, −y+3/2, −z+1; (ii) −x+1/2, y+1/2, −z+1/2; (iii) x−1/2, −y+1/2, z−1/2; (iv) −x, y, −z+1/2; (v) −x+1/2, y−1/2, −z+1/2; (vi) x, −y+1, z−1/2; (vii) x+1/2, −y+1/2, z+1/2; (viii) x, −y+1, z+1/2.