K_5.76Ga_5.76Si_10.24O₃₂·3.4H₂O, a gallosilicate with the zeolite gismondine topology

The title compound, K-GaSi-GIS, potassium gallium silicon oxide hydrate, was synthesized hydro­thermally and its crystal structure was determined from data collected on a single crystal of dimensions 10 × 10 × 8 µm at a synchrotron X-ray source. The compound, which has the aluminosilicate (AlSi) zeolite gismondine (GIS) topology, Ca₄[Al₈Si₈O₃₂]·16H₂O, crystallizes in the tetragonal space group I4₁/a. A disordered distribution of the framework Si/Ga sites leads to higher symmetry of the GIS-type network compared with the usual monoclinic symmetry in AlSi-GIS. Framework Ga substitution for Al in AlSi-GIS leads to substantial distortion of the crankshaft chains, reducing the effective pore dimensions and suggesting the possibility of pore-dimension control via partial framework-cation substitution.

Computing details

Data collection: SMART (Bruker AXS, 1996); cell refinement: SMART; data reduction: SAINT (Bruker AXS, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: CrystalMaker (Palmer, 2000); software used to prepare material for publication: SHELXL97.

(I)

Crystal data

K5.76Ga5.76Si10.24O32·3.4H2O	Dx = 2.647 Mg m^−3
Mr = 1484.40	Synchrotron radiation, λ = 0.6430 Å
Tetragonal, I41/a	Cell parameters from 5045 reflections
Hall symbol: -I 4ad	θ = 2.6–30.6°
a = 9.9639 (6) Å	µ = 5.20 mm^−1
c = 9.3806 (9) Å	T = 298 K
V = 931.3 (1) Å^3	Octahedral, colourless
Z = 1	0.01 × 0.01 × 0.01 mm
F(000) = 715

Data collection

Bruker SMART CCD area detector diffractometer	939 independent reflections
Radiation source: Synchrotron	749 reflections with I > 2σ(I)
Si(111) monochromator	Rint = 0.094
Detector resolution: 0.70 pixels mm^-1	θmax = 30.6°, θmin = 2.6°
φ scans	h = −15→15
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −15→15
Tmin = 0.949, Tmax = 0.959	l = −14→14
5111 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.067	H-atom parameters not defined
wR(F^2) = 0.156	w = 1/[σ^2(Fo^2) + (0.046P)^2 + 15.7958P] where P = (Fo^2 + 2Fc^2)/3
S = 1.13	(Δ/σ)max < 0.001
939 reflections	Δρmax = 1.19 e Å^−3
47 parameters	Δρmin = −0.97 e Å^−3
0 restraints

Special details

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 individual site occupancies for Ga, Si, K1 and OW1 refined to 37, 64.6, 36 and 21% respectively. In conjunction with an established empirical formula (K₆Ga₆Si_10.5O₃₆) from EPMA these were fixed to 36, 64, 36 and 21% level respectively in the final cycle of the refinement.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Ga1	0.32466 (8)	0.62521 (8)	0.08729 (8)	0.0117 (2)	0.36
Si1	0.32466 (8)	0.62521 (8)	0.08729 (8)	0.0117 (2)	0.64
O1	0.3199 (6)	0.7937 (5)	0.0689 (5)	0.0363 (10)
O2	0.3218 (5)	0.5660 (4)	−0.0810 (5)	0.0327 (10)
K1	0.1712 (12)	0.7056 (7)	−0.2649 (6)	0.099 (3)	0.36
OW1	0.057 (3)	0.731 (3)	−0.215 (3)	0.057 (8)	0.21

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ga1	0.0121 (4)	0.0124 (4)	0.0107 (3)	−0.0002 (3)	0.0028 (3)	−0.0017 (3)
Si1	0.0121 (4)	0.0124 (4)	0.0107 (3)	−0.0002 (3)	0.0028 (3)	−0.0017 (3)
O1	0.052 (3)	0.023 (2)	0.034 (2)	0.0019 (19)	−0.006 (2)	−0.0013 (18)
O2	0.049 (3)	0.023 (2)	0.0257 (19)	0.0059 (18)	0.009 (2)	−0.0019 (16)
K1	0.210 (11)	0.054 (4)	0.033 (3)	0.057 (5)	−0.002 (4)	0.017 (3)
OW1	0.09 (2)	0.023 (12)	0.053 (15)	0.000 (13)	0.026 (15)	−0.003 (11)

Geometric parameters (Å, º)

Ga1—O1^i	1.673 (5)	K1—K1^iii	1.82 (2)
Ga1—O2^ii	1.684 (4)	K1—OW1^vii	2.43 (4)
Ga1—O2	1.686 (5)	K1—O2^iii	2.697 (7)
Ga1—O1	1.688 (5)	K1—OW1^iii	2.76 (4)
Ga1—K1^iii	3.462 (5)	K1—OW1^viii	2.84 (3)
Ga1—K1^iv	3.576 (7)	K1—O1^iii	2.852 (8)
Ga1—K1^ii	3.584 (7)	K1—OW1^v	2.89 (3)
Ga1—K1	3.728 (6)	K1—O1^v	3.066 (11)
Ga1—K1^v	3.768 (6)	K1—O2^ix	3.178 (8)
Ga1—K1^vi	3.979 (7)	K1—Ga1^iii	3.462 (5)
K1—O2	2.676 (8)	OW1—OW1^vii	1.25 (7)
K1—OW1	1.23 (3)
O1^i—Ga1—O2^ii	108.0 (2)	OW1—K1—OW1^iii	148.9 (12)
O1^i—Ga1—O2	113.0 (3)	K1^iii—K1—OW1^iii	20.4 (6)
O2^ii—Ga1—O2	107.5 (3)	OW1^vii—K1—OW1^iii	150.6 (11)
O1^i—Ga1—O1	113.8 (4)	O2—K1—OW1^iii	67.4 (6)
O2^ii—Ga1—O1	109.7 (3)	O2^iii—K1—OW1^iii	75.3 (6)
O2—Ga1—O1	104.6 (2)	OW1—K1—OW1^viii	32.8 (19)
O1^i—Ga1—K1^iii	127.6 (3)	K1^iii—K1—OW1^viii	99.4 (8)
O2^ii—Ga1—K1^iii	124.1 (3)	OW1^vii—K1—OW1^viii	42.0 (10)
O2—Ga1—K1^iii	49.66 (19)	O2—K1—OW1^viii	89.8 (7)
O1—Ga1—K1^iii	55.0 (2)	O2^iii—K1—OW1^viii	96.6 (8)
O1^i—Ga1—K1^iv	58.9 (3)	OW1^iii—K1—OW1^viii	118.8 (10)
O2^ii—Ga1—K1^iv	62.7 (2)	OW1—K1—O1^iii	113.5 (16)
O2—Ga1—K1^iv	92.32 (18)	K1^iii—K1—O1^iii	97.2 (5)
O1—Ga1—K1^iv	163.05 (19)	OW1^vii—K1—O1^iii	102.5 (7)
K1^iii—Ga1—K1^iv	141.93 (13)	O2—K1—O1^iii	128.9 (3)
O1^i—Ga1—K1^ii	124.4 (3)	O2^iii—K1—O1^iii	57.43 (17)
O2^ii—Ga1—K1^ii	45.1 (2)	OW1^iii—K1—O1^iii	84.6 (7)
O2—Ga1—K1^ii	62.4 (2)	OW1^viii—K1—O1^iii	141.2 (7)
O1—Ga1—K1^ii	121.0 (3)	OW1—K1—OW1^v	30.2 (17)
K1^iii—Ga1—K1^ii	93.0 (3)	K1^iii—K1—OW1^v	118.4 (7)
K1^iv—Ga1—K1^ii	65.79 (2)	OW1^vii—K1—OW1^v	41.4 (9)
O1^i—Ga1—K1	149.2 (2)	O2—K1—OW1^v	81.8 (6)
O2^ii—Ga1—K1	97.5 (2)	O2^iii—K1—OW1^v	117.6 (7)
O2—Ga1—K1	40.35 (19)	OW1^iii—K1—OW1^v	134.3 (11)
O1—Ga1—K1	71.6 (2)	OW1^viii—K1—OW1^v	25.1 (14)
K1^iii—Ga1—K1	29.1 (4)	O1^iii—K1—OW1^v	140.5 (7)
K1^iv—Ga1—K1	123.11 (12)	OW1—K1—O1^v	82.5 (15)
K1^ii—Ga1—K1	64.22 (11)	K1^iii—K1—O1^v	144.7 (6)
O1^i—Ga1—K1^v	145.0 (2)	OW1^vii—K1—O1^v	82.7 (7)
O2^ii—Ga1—K1^v	39.71 (19)	O2—K1—O1^v	82.7 (2)
O2—Ga1—K1^v	76.8 (2)	O2^iii—K1—O1^v	132.7 (3)
O1—Ga1—K1^v	94.4 (3)	OW1^iii—K1—O1^v	126.7 (6)
K1^iii—Ga1—K1^v	85.08 (14)	OW1^viii—K1—O1^v	103.4 (7)
K1^iv—Ga1—K1^v	88.2 (4)	O1^iii—K1—O1^v	81.4 (2)
K1^ii—Ga1—K1^v	28.6 (4)	OW1^v—K1—O1^v	78.8 (7)
K1—Ga1—K1^v	57.8 (3)	OW1—K1—O2^ix	131.4 (14)
O1^i—Ga1—K1^vi	38.0 (2)	K1^iii—K1—O2^ix	93.5 (5)
O2^ii—Ga1—K1^vi	79.02 (18)	OW1^vii—K1—O2^ix	133.9 (7)
O2—Ga1—K1^vi	147.5 (2)	O2—K1—O2^ix	54.51 (13)
O1—Ga1—K1^vi	102.8 (2)	O2^iii—K1—O2^ix	128.1 (3)
K1^iii—Ga1—K1^vi	150.6 (3)	OW1^iii—K1—O2^ix	75.3 (6)
K1^iv—Ga1—K1^vi	61.69 (11)	OW1^viii—K1—O2^ix	135.0 (8)
K1^ii—Ga1—K1^vi	116.13 (11)	O1^iii—K1—O2^ix	78.1 (2)
K1—Ga1—K1^vi	172.1 (2)	OW1^v—K1—O2^ix	113.6 (7)
K1^v—Ga1—K1^vi	118.32 (13)	O1^v—K1—O2^ix	51.52 (16)
Si1^x—O1—Ga1	135.8 (3)	OW1—K1—Ga1^iii	103.6 (14)
Si1^x—O1—K1^iii	120.9 (3)	K1^iii—K1—Ga1^iii	83.6 (4)
Ga1—O1—K1^iii	96.0 (2)	OW1^vii—K1—Ga1^iii	92.8 (7)
Si1^x—O1—K1^viii	93.3 (3)	O2—K1—Ga1^iii	144.0 (4)
Ga1—O1—K1^viii	117.0 (3)	O2^iii—K1—Ga1^iii	28.46 (11)
K1^iii—O1—K1^viii	82.1 (2)	OW1^iii—K1—Ga1^iii	79.7 (7)
Si1^ix—O2—Ga1	135.4 (3)	OW1^viii—K1—Ga1^iii	119.7 (8)
Si1^ix—O2—K1	108.5 (3)	O1^iii—K1—Ga1^iii	29.01 (11)
Ga1—O2—K1	115.6 (3)	OW1^v—K1—Ga1^iii	133.6 (6)
Si1^ix—O2—K1^iii	116.8 (3)	O1^v—K1—Ga1^iii	107.3 (2)
Ga1—O2—K1^iii	101.9 (2)	O2^ix—K1—Ga1^iii	104.3 (2)
K1—O2—K1^iii	39.7 (5)	K1—OW1—OW1^vii	157.6 (16)
Si1^ix—O2—K1^ii	89.2 (3)	K1—OW1—K1^vii	147 (2)
Ga1—O2—K1^ii	89.5 (2)	OW1^vii—OW1—K1^vii	11.1 (8)
K1—O2—K1^ii	82.78 (17)	K1—OW1—K1^iii	31.1 (12)
K1^iii—O2—K1^ii	120.7 (5)	OW1^vii—OW1—K1^iii	149 (3)
OW1—K1—K1^iii	128.5 (16)	K1^vii—OW1—K1^iii	148.0 (12)
OW1—K1—OW1^vii	11.3 (10)	K1—OW1—K1^v	120.3 (17)
K1^iii—K1—OW1^vii	131.2 (8)	OW1^vii—OW1—K1^v	79.5 (19)
OW1—K1—O2	112.0 (14)	K1^vii—OW1—K1^v	86.4 (9)
K1^iii—K1—O2	70.8 (4)	K1^iii—OW1—K1^v	121.7 (12)
OW1^vii—K1—O2	123.0 (7)	K1—OW1—K1^viii	117 (2)
OW1—K1—O2^iii	92.9 (13)	OW1^vii—OW1—K1^viii	75.4 (15)
K1^iii—K1—O2^iii	69.5 (4)	K1^vii—OW1—K1^viii	85.4 (8)
OW1^vii—K1—O2^iii	84.5 (7)	K1^iii—OW1—K1^viii	87.0 (10)
O2—K1—O2^iii	140.3 (5)	K1^v—OW1—K1^viii	75.9 (7)

Symmetry codes: (i) −y+5/4, x+1/4, −z+1/4; (ii) −y+3/4, x+1/4, z+1/4; (iii) −x+1/2, −y+3/2, −z−1/2; (iv) −x+1/2, −y+1, z+1/2; (v) y−3/4, −x+3/4, −z−1/4; (vi) y−1/4, −x+3/4, z+3/4; (vii) −x, −y+3/2, z; (viii) −y+3/4, x+3/4, −z−1/4; (ix) y−1/4, −x+3/4, z−1/4; (x) y−1/4, −x+5/4, −z+1/4.