Rb2Lu[Si4O10]F, a tubular chain silicate.

Single crystals of Rb2Lu[Si4O10]F (dirubidium lutetium tetra-silicate fluoride) were obtained in flux-synthesis experiments in the system SiO2-Lu2O3-RbF. The compound belongs to the group of tubular chain silicates, i.e. it is based on multiple chains of condensed [SiO4] tetra-hedra forming closed columns. The periodicity of the unbranched multiple chains is four and corresponds to the length of the b axis. Adjacent columns are connected by Lu(3+) cations, which are coordinated by four oxide and two fluoride anions in the form of slightly distorted octa-hedra. By sharing common fluoride corners, the single octa-hedra are linked into chains running parallel to the silicate tubes. Electroneutrality is achieved by the incorporation of additional Rb(+) cations. All four symmetrically independent rubidium ions, four out of twelve oxide as well as the two fluoride anions are located on mirror planes. The remaining atoms reside on general positions.

Related literature

Oxosilicates that contain monovalent alkali cations, trivalent rare earth elements and additional fluorine anions have potential application in the field of luminescense (Jacobsen & Meyer, 1994 ▶; Tang et al., 2008 ▶; Schäfer & Schleid, 2007 ▶, 2011 ▶; Kahlenberg & Manninger, 2014 ▶). For structures isotypic to that of the title compound, see: Chigarov et al. (1983 ▶); Hung et al. (2003 ▶). For general aspects of the crystal chemistry of silicates, see: Liebau (1985 ▶). For the definition of distortion parameters, see: Robinson et al. (1971 ▶). For bond-valence analysis, see: Brown (2002 ▶). For the definition and calculation of similarity descriptors, see: Tasci et al. (2012 ▶); Bergerhoff et al. (1999 ▶). For the Inorganic Structure Database, see: ICSD (2014 ▶).

Experimental

Crystal data

Rb2Lu[Si4O10]F

M = 637.27

Monoclinic,

a = 11.6695 (3) Å

b = 8.52379 (18) Å

c = 11.8165 (3) Å

β = 111.753 (3)°

V = 1091.67 (5) Å3

Z = 4

Mo Kα radiation

μ = 18.4 mm−1

T = 298 K

0.32 × 0.08 × 0.08 mm

Data collection

Oxford Diffraction Xcalibur (Ruby, Gemini ultra) diffractometer

Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2006 ▶), based on expressions derived by Clark & Reid (1995 ▶)] T min = 0.106, T max = 0.562

15185 measured reflections

2388 independent reflections

2276 reflections with I > 2σ(I)

R int = 0.028

Refinement

R[F 2 > 2σ(F 2)] = 0.017

wR(F 2) = 0.037

S = 1.2

2388 reflections

178 parameters

Δρmax = 0.67 e Å−3

Δρmin = −0.69 e Å−3

Data collection: CrysAlis PRO (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2003 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ATOMS for Windows (Dowty, 2011 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶) and WinGX (Farrugia, 2012 ▶).

Crystal structure: contains datablock(s) global, I, New_Global_Publ_Block. DOI: 10.1107/S1600536814003043/wm5002sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536814003043/wm5002Isup2.hkl

CCDC reference: 986192

Additional supporting information: crystallographic information; 3D view; checkCIF report

Rb2Lu[Si4O10]F	F(000) = 1160
Mr = 637.27	Dx = 3.877 Mg m−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yb	Cell parameters from 8764 reflections
a = 11.6695 (3) Å	θ = 3.0–29.4°
b = 8.52379 (18) Å	µ = 18.4 mm−1
c = 11.8165 (3) Å	T = 298 K
β = 111.753 (3)°	Prism, colourless
V = 1091.67 (5) Å3	0.32 × 0.08 × 0.08 mm
Z = 4

Oxford Diffraction Xcalibur (Ruby, Gemini ultra) diffractometer	2388 independent reflections
Graphite monochromator	2276 reflections with I > 2σ(I)
Detector resolution: 10.3575 pixels mm-1	Rint = 0.028
ω scans	θmax = 26.4°, θmin = 3.0°
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2006), based on expressions derived by Clark & Reid (1995)]	h = −14→14
Tmin = 0.106, Tmax = 0.562	k = −10→10
15185 measured reflections	l = −14→14

Refinement on F2	0 constraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.017	Secondary atom site location: difference Fourier map
wR(F2) = 0.037	w = 1/[σ2(Fo2) + (0.008P)2 + 3.5409P] where P = (Fo2 + 2Fc2)/3
S = 1.2	(Δ/σ)max = 0.001
2388 reflections	Δρmax = 0.67 e Å−3
178 parameters	Δρmin = −0.69 e Å−3
0 restraints

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.

	x	y	z	Uiso*/Ueq
Lu	0.293348 (13)	0.003290 (17)	0.709429 (13)	0.00494 (5)
Rb1	0.44695 (5)	0.75	0.54955 (5)	0.01305 (11)
Rb2	0.08212 (5)	0.25	0.07908 (5)	0.01314 (11)
Rb3	−0.00057 (5)	0.75	0.52863 (5)	0.01827 (13)
Rb4	0.46419 (5)	0.25	0.03113 (5)	0.01750 (12)
Si1	0.38671 (9)	−0.06260 (11)	0.22969 (8)	0.00464 (19)
Si2	0.01773 (9)	0.06858 (11)	0.75550 (9)	0.00508 (19)
Si3	0.24334 (9)	0.43354 (11)	0.38343 (8)	0.00493 (19)
Si4	0.22493 (9)	0.93232 (11)	0.96450 (8)	0.00543 (19)
O1	0.4021 (3)	0.75	0.2204 (3)	0.0099 (8)
O2	0.7259 (3)	0.75	0.6326 (4)	0.0129 (8)
O3	0.2743 (2)	0.9946 (3)	0.1053 (2)	0.0084 (5)
O4	0.3423 (2)	0.9684 (3)	0.3435 (2)	0.0100 (5)
O5	−0.0274 (3)	0.25	0.7485 (3)	0.0112 (8)
O6	−0.1052 (2)	0.9599 (3)	0.7182 (2)	0.0090 (5)
O7	0.0945 (2)	0.0289 (3)	0.9002 (2)	0.0084 (5)
O8	0.1833 (3)	0.75	0.9630 (3)	0.0100 (8)
O9	0.5102 (2)	0.0289 (3)	0.2481 (2)	0.0110 (5)
O10	0.0957 (2)	0.0320 (3)	0.6743 (2)	0.0096 (5)
O11	0.3210 (2)	0.9616 (3)	0.9020 (2)	0.0095 (5)
O12	0.2534 (3)	0.0222 (3)	0.5157 (2)	0.0156 (6)
F1	0.2695 (3)	0.75	0.6782 (3)	0.0142 (7)
F2	0.3190 (3)	0.25	0.7478 (3)	0.0172 (7)

	U11	U22	U33	U12	U13	U23
Lu	0.00544 (8)	0.00452 (8)	0.00516 (8)	0.00016 (5)	0.00231 (6)	0.00015 (5)
Rb1	0.0146 (3)	0.0120 (2)	0.0119 (2)	0	0.0043 (2)	0
Rb2	0.0170 (3)	0.0114 (2)	0.0131 (2)	0	0.0080 (2)	0
Rb3	0.0248 (3)	0.0133 (3)	0.0122 (3)	0	0.0016 (2)	0
Rb4	0.0143 (3)	0.0133 (3)	0.0212 (3)	0	0.0024 (2)	0
Si1	0.0050 (5)	0.0044 (4)	0.0044 (4)	0.0007 (4)	0.0015 (4)	0.0002 (4)
Si2	0.0043 (5)	0.0047 (5)	0.0053 (4)	0.0002 (4)	0.0007 (4)	0.0003 (4)
Si3	0.0049 (5)	0.0052 (5)	0.0044 (4)	−0.0007 (4)	0.0013 (4)	−0.0001 (4)
Si4	0.0055 (5)	0.0057 (5)	0.0042 (4)	0.0006 (4)	0.0009 (4)	0.0007 (4)
O1	0.0112 (19)	0.0054 (17)	0.0149 (19)	0	0.0071 (16)	0
O2	0.0094 (19)	0.0051 (17)	0.021 (2)	0	0.0015 (16)	0
O3	0.0070 (12)	0.0113 (13)	0.0050 (12)	0.0022 (10)	0.0001 (10)	−0.0006 (10)
O4	0.0100 (13)	0.0113 (13)	0.0101 (12)	0.0043 (10)	0.0053 (11)	−0.0006 (10)
O5	0.0093 (19)	0.0069 (18)	0.0156 (19)	0	0.0027 (16)	0
O6	0.0048 (12)	0.0099 (12)	0.0097 (12)	−0.0021 (10)	−0.0002 (10)	−0.0001 (10)
O7	0.0074 (13)	0.0118 (13)	0.0063 (12)	0.0036 (10)	0.0029 (10)	−0.0007 (10)
O8	0.0134 (19)	0.0035 (17)	0.0127 (18)	0	0.0045 (16)	0
O9	0.0082 (13)	0.0091 (13)	0.0145 (13)	−0.0019 (10)	0.0028 (11)	−0.0004 (11)
O10	0.0084 (13)	0.0127 (13)	0.0076 (12)	0.0016 (10)	0.0030 (10)	0.0011 (10)
O11	0.0089 (13)	0.0137 (13)	0.0069 (12)	0.0010 (10)	0.0042 (10)	0.0023 (10)
O12	0.0179 (15)	0.0221 (15)	0.0075 (12)	0.0039 (11)	0.0054 (11)	0.0023 (11)
F1	0.0164 (17)	0.0044 (14)	0.0194 (17)	0	0.0039 (14)	0
F2	0.0220 (18)	0.0056 (15)	0.0250 (18)	0	0.0100 (15)	0

Si1—O9	1.581 (3)	Rb1—O4xi	3.332 (3)
Si1—O1i	1.6157 (11)	Rb2—O7xii	2.875 (2)
Si1—O4i	1.631 (3)	Rb2—O7xiii	2.875 (2)
Si1—O3i	1.640 (2)	Rb2—O6iii	2.921 (3)
Si2—O10	1.579 (3)	Rb2—O6xiv	2.921 (3)
Si2—O6i	1.625 (3)	Rb2—O8xiv	2.949 (4)
Si2—O5	1.6259 (14)	Rb2—O3iv	3.058 (2)
Si2—O7	1.645 (3)	Rb2—O3i	3.058 (2)
Si3—O12ii	1.569 (3)	Rb2—O7xv	3.214 (3)
Si3—O6iii	1.630 (3)	Rb2—O7xvi	3.214 (3)
Si3—O4iv	1.631 (3)	Rb2—O2v	3.312 (4)
Si3—O2v	1.6318 (15)	Rb3—O10xvi	2.909 (3)
Si4—O11	1.574 (3)	Rb3—O10xiv	2.909 (2)
Si4—O8	1.6264 (14)	Rb3—O10vii	2.927 (3)
Si4—O3vi	1.634 (3)	Rb3—O10ii	2.927 (3)
Si4—O7vii	1.648 (3)	Rb3—F1	2.988 (3)
Lu—F2	2.1487 (7)	Rb3—O12xvi	3.407 (3)
Lu—O12	2.167 (3)	Rb3—O12xiv	3.407 (3)
Lu—O9viii	2.175 (3)	Rb3—O5xiv	3.409 (4)
Lu—F1i	2.1906 (6)	Rb3—O6	3.426 (3)
Lu—O10	2.200 (2)	Rb3—O6iv	3.426 (3)
Lu—O11i	2.205 (2)	Rb4—O11xi	2.949 (3)
Rb1—O9v	2.938 (3)	Rb4—O11v	2.949 (3)
Rb1—O9ix	2.938 (3)	Rb4—O11xvii	3.045 (3)
Rb1—O4iv	2.947 (3)	Rb4—O11xviii	3.045 (3)
Rb1—O4	2.947 (3)	Rb4—O9ii	3.065 (3)
Rb1—F1	2.989 (3)	Rb4—O9	3.065 (3)
Rb1—O2	3.031 (4)	Rb4—F2xii	3.142 (3)
Rb1—O12ii	3.158 (3)	Rb4—O3iv	3.444 (3)
Rb1—O12vii	3.158 (3)	Rb4—O3i	3.444 (3)
Rb1—O4x	3.332 (3)
F2—Lu—O12	96.25 (12)	O6i—Si2—O7	104.51 (14)
F2—Lu—O9viii	91.29 (11)	O5—Si2—O7	106.84 (17)
O12—Lu—O9viii	92.79 (10)	O12ii—Si3—O6iii	112.89 (15)
F2—Lu—F1i	177.69 (12)	O12ii—Si3—O4iv	111.44 (15)
O12—Lu—F1i	86.05 (11)	O6iii—Si3—O4iv	109.22 (14)
O9viii—Lu—F1i	88.38 (11)	O12ii—Si3—O2v	114.08 (18)
F2—Lu—O10	89.16 (11)	O6iii—Si3—O2v	104.29 (16)
O12—Lu—O10	89.57 (10)	O4iv—Si3—O2v	104.34 (17)
O9viii—Lu—O10	177.53 (9)	O11—Si4—O8	114.10 (17)
F1i—Lu—O10	91.08 (11)	O11—Si4—O3vi	112.49 (14)
F2—Lu—O11i	89.10 (11)	O8—Si4—O3vi	108.21 (17)
O12—Lu—O11i	173.81 (10)	O11—Si4—O7vii	113.66 (14)
O9viii—Lu—O11i	90.18 (9)	O8—Si4—O7vii	104.55 (16)
F1i—Lu—O11i	88.61 (11)	O3vi—Si4—O7vii	102.93 (13)
O10—Lu—O11i	87.40 (9)	Si1vii—O1—Si1ii	162.7 (3)
O9—Si1—O1i	112.24 (17)	Si3ix—O2—Si3v	146.9 (3)
O9—Si1—O4i	110.99 (14)	Si4xii—O3—Si1vii	132.77 (16)
O1i—Si1—O4i	107.06 (17)	Si3iv—O4—Si1vii	142.83 (17)
O9—Si1—O3i	111.24 (14)	Si2ii—O5—Si2	144.0 (2)
O1i—Si1—O3i	107.75 (16)	Si2vii—O6—Si3xvi	144.19 (17)
O4i—Si1—O3i	107.32 (13)	Si2—O7—Si4i	129.48 (16)
O10—Si2—O6i	111.85 (14)	Si4—O8—Si4iv	145.7 (3)
O10—Si2—O5	113.95 (17)	Luvii—F1—Luii	160.51 (16)
O6i—Si2—O5	106.95 (16)	Lu—F2—Luii	156.30 (18)
O10—Si2—O7	112.13 (14)