Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103023151/gd1279sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103023151/gd1279Isup2.hkl |
CCDC reference: 229067
The title compound was prepared using the patented procedure of Krätsmár-Šmogrovič et al. (1991), by reaction of the corresponding aqua complex Cu(sal-β-ala)(H2O) (Werner et al., 1983) with potassium thiocyanate in an ethanol-water solution. The reaction mixture was made up of Cu(sal-β-ala)(H2O) (20 mmol, 5.45 g) and KSCN (80 mmol, 7.77 g) dissolved in ethanol-water (240 ml, 2:1 v/v), and it was then heated to 333 K and mixed vigorously for 60 min until the solid phase disappeared. The solution was filtered and left to cool to room temperature. Dark-green well developed crystals of (I) were isolated and analyzed. Analysis (Carlo-Erba 1180 instrument) calculated for C11H9CuKN2O3S: C 37.5, H 2.6, N 8.0%; found: C 37.7, H 2.6, N 7.9%. Single crystals of (I) for diffraction analysis were prepared by the diffusion method from a propan-2-ol solution using CHCl3 as the precipitant.
All H atoms were located from difference maps. They were then treated as riding atoms with C—H distances of 0.95 or 0.99 Å.
Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED (Oxford Diffraction, 2002); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Johnson & Burnett, 1996); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).
K[Cu(NCS)(C10H9NO3)] | F(000) = 1416 |
Mr = 351.90 | Dx = 1.817 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 3558 reflections |
a = 12.5103 (7) Å | θ = 2.3–31.0° |
b = 8.4276 (6) Å | µ = 2.19 mm−1 |
c = 24.401 (2) Å | T = 120 K |
V = 2572.6 (3) Å3 | Prism, dark green |
Z = 8 | 0.40 × 0.30 × 0.15 mm |
Kuma KM-4 with a CCD area detector diffractometer | 2248 independent reflections |
Radiation source: fine-focus sealed tube | 2040 reflections with I > 2σ(I) |
Enhance (Oxford Diffraction) monochromator | Rint = 0.044 |
Detector resolution: 16.3 pixels mm-1 | θmax = 25.0°, θmin = 3.0° |
rotation method, ω scans | h = −14→14 |
Absorption correction: analytical CrysAlis RED (Oxford Diffraction, 2002) | k = −10→8 |
Tmin = 0.444, Tmax = 0.750 | l = −28→28 |
10607 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.033 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.080 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.04P)2 + 5P] where P = (Fo2 + 2Fc2)/3 |
2248 reflections | (Δ/σ)max = 0.001 |
172 parameters | Δρmax = 0.45 e Å−3 |
0 restraints | Δρmin = −0.42 e Å−3 |
K[Cu(NCS)(C10H9NO3)] | V = 2572.6 (3) Å3 |
Mr = 351.90 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 12.5103 (7) Å | µ = 2.19 mm−1 |
b = 8.4276 (6) Å | T = 120 K |
c = 24.401 (2) Å | 0.40 × 0.30 × 0.15 mm |
Kuma KM-4 with a CCD area detector diffractometer | 2248 independent reflections |
Absorption correction: analytical CrysAlis RED (Oxford Diffraction, 2002) | 2040 reflections with I > 2σ(I) |
Tmin = 0.444, Tmax = 0.750 | Rint = 0.044 |
10607 measured reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.080 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.45 e Å−3 |
2248 reflections | Δρmin = −0.42 e Å−3 |
172 parameters |
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 | ||
Cu | 0.53960 (3) | 0.25752 (4) | 0.565256 (14) | 0.01086 (13) | |
K | 0.67949 (5) | 0.64082 (7) | 0.56987 (3) | 0.01340 (17) | |
S | 0.57408 (6) | 0.45473 (9) | 0.39460 (3) | 0.01473 (19) | |
O1 | 0.43047 (16) | 0.2016 (2) | 0.51065 (9) | 0.0130 (4) | |
O2 | 0.35931 (16) | 0.0046 (2) | 0.46337 (8) | 0.0143 (5) | |
O3 | 0.65687 (16) | 0.3159 (2) | 0.61194 (8) | 0.0128 (4) | |
N1 | 0.46025 (18) | 0.1561 (3) | 0.62445 (10) | 0.0114 (5) | |
N2 | 0.6113 (2) | 0.3736 (3) | 0.50398 (11) | 0.0133 (5) | |
C1 | 0.3853 (2) | 0.0644 (3) | 0.50777 (13) | 0.0119 (6) | |
C2 | 0.3644 (2) | −0.0216 (4) | 0.56086 (12) | 0.0139 (6) | |
H2A | 0.4231 | −0.0983 | 0.5674 | 0.017* | |
H2B | 0.2972 | −0.0827 | 0.5574 | 0.017* | |
C3 | 0.3558 (2) | 0.0888 (4) | 0.60999 (13) | 0.0134 (6) | |
H3A | 0.3054 | 0.1759 | 0.6014 | 0.016* | |
H3B | 0.3270 | 0.0294 | 0.6417 | 0.016* | |
C4 | 0.4864 (2) | 0.1592 (4) | 0.67532 (13) | 0.0133 (6) | |
H4 | 0.4382 | 0.1112 | 0.7004 | 0.016* | |
C5 | 0.5818 (2) | 0.2285 (3) | 0.69791 (13) | 0.0137 (6) | |
C6 | 0.6616 (2) | 0.3029 (3) | 0.66566 (13) | 0.0130 (6) | |
C7 | 0.7518 (3) | 0.3644 (4) | 0.69284 (13) | 0.0169 (7) | |
H7 | 0.8064 | 0.4151 | 0.6722 | 0.020* | |
C8 | 0.7623 (3) | 0.3523 (4) | 0.74892 (14) | 0.0219 (7) | |
H8 | 0.8242 | 0.3944 | 0.7662 | 0.026* | |
C9 | 0.6844 (3) | 0.2800 (4) | 0.78067 (14) | 0.0206 (7) | |
H9 | 0.6926 | 0.2720 | 0.8193 | 0.025* | |
C10 | 0.5949 (3) | 0.2200 (4) | 0.75529 (13) | 0.0178 (7) | |
H10 | 0.5407 | 0.1719 | 0.7769 | 0.021* | |
C11 | 0.5962 (2) | 0.4084 (3) | 0.45867 (13) | 0.0110 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu | 0.0082 (2) | 0.0128 (2) | 0.0116 (2) | −0.00258 (14) | −0.00068 (14) | 0.00127 (15) |
K | 0.0097 (3) | 0.0134 (3) | 0.0171 (4) | 0.0004 (2) | −0.0013 (3) | −0.0015 (3) |
S | 0.0136 (4) | 0.0174 (4) | 0.0132 (4) | 0.0032 (3) | 0.0007 (3) | 0.0008 (3) |
O1 | 0.0105 (10) | 0.0125 (11) | 0.0161 (11) | −0.0024 (8) | −0.0018 (8) | 0.0012 (9) |
O2 | 0.0106 (10) | 0.0177 (11) | 0.0147 (11) | −0.0007 (8) | −0.0014 (9) | −0.0027 (9) |
O3 | 0.0105 (10) | 0.0156 (11) | 0.0123 (11) | −0.0008 (8) | −0.0013 (8) | −0.0004 (9) |
N1 | 0.0087 (12) | 0.0103 (12) | 0.0151 (14) | 0.0019 (10) | 0.0001 (10) | 0.0005 (10) |
N2 | 0.0128 (13) | 0.0119 (13) | 0.0152 (15) | −0.0023 (10) | 0.0014 (10) | −0.0015 (11) |
C1 | 0.0043 (13) | 0.0133 (15) | 0.0181 (17) | 0.0034 (11) | −0.0003 (12) | −0.0006 (12) |
C2 | 0.0109 (14) | 0.0116 (15) | 0.0191 (16) | −0.0021 (12) | −0.0018 (12) | −0.0001 (13) |
C3 | 0.0093 (14) | 0.0145 (15) | 0.0163 (16) | −0.0021 (11) | 0.0026 (12) | 0.0013 (12) |
C4 | 0.0145 (15) | 0.0106 (15) | 0.0147 (16) | 0.0028 (12) | 0.0051 (12) | 0.0024 (12) |
C5 | 0.0151 (15) | 0.0103 (15) | 0.0158 (16) | 0.0031 (12) | −0.0013 (13) | −0.0021 (12) |
C6 | 0.0152 (15) | 0.0072 (14) | 0.0166 (16) | 0.0038 (11) | −0.0032 (13) | −0.0028 (12) |
C7 | 0.0170 (15) | 0.0131 (16) | 0.0207 (16) | −0.0027 (12) | −0.0047 (14) | −0.0006 (13) |
C8 | 0.0247 (17) | 0.0161 (17) | 0.0248 (18) | −0.0004 (13) | −0.0118 (15) | −0.0015 (14) |
C9 | 0.032 (2) | 0.0144 (16) | 0.0152 (17) | 0.0019 (14) | −0.0077 (14) | −0.0004 (13) |
C10 | 0.0258 (17) | 0.0137 (16) | 0.0140 (16) | 0.0030 (13) | 0.0010 (14) | 0.0009 (13) |
C11 | 0.0058 (13) | 0.0074 (14) | 0.0197 (18) | −0.0011 (11) | 0.0017 (12) | −0.0024 (12) |
Cu—O3 | 1.921 (2) | N1—C3 | 1.467 (4) |
Cu—N1 | 1.950 (3) | N2—C11 | 1.159 (4) |
Cu—O1 | 1.965 (2) | C1—C2 | 1.508 (4) |
Cu—N2 | 1.999 (3) | C2—C3 | 1.522 (4) |
Cu—O2i | 2.639 (2) | C2—H2A | 0.9900 |
Cu—Sii | 2.9771 (8) | C2—H2B | 0.9900 |
Cu—Kiii | 3.6510 (7) | C3—H3A | 0.9900 |
Cu—K | 3.6756 (7) | C3—H3B | 0.9900 |
K—O2iv | 2.687 (2) | C4—C5 | 1.439 (4) |
K—O3v | 2.724 (2) | C4—H4 | 0.9500 |
K—O1ii | 2.742 (2) | C5—C10 | 1.411 (4) |
K—N2 | 2.895 (3) | C5—C6 | 1.418 (5) |
K—O3 | 2.938 (2) | C6—C7 | 1.407 (4) |
K—O2ii | 3.134 (2) | C7—C8 | 1.378 (5) |
K—Sii | 3.3857 (10) | C7—H7 | 0.9500 |
S—C11 | 1.635 (3) | C8—C9 | 1.386 (5) |
O1—C1 | 1.288 (4) | C8—H8 | 0.9500 |
O2—C1 | 1.239 (4) | C9—C10 | 1.376 (5) |
O3—C6 | 1.317 (4) | C9—H9 | 0.9500 |
N1—C4 | 1.284 (4) | C10—H10 | 0.9500 |
O3—Cu—N1 | 93.55 (10) | Cu—N2—K | 95.60 (9) |
O3—Cu—O1 | 173.66 (9) | O2—C1—O1 | 121.9 (3) |
N1—Cu—O1 | 92.48 (9) | O2—C1—C2 | 120.7 (3) |
O3—Cu—N2 | 88.61 (10) | O1—C1—C2 | 117.4 (3) |
N1—Cu—N2 | 175.43 (10) | O2—C1—Kii | 74.57 (17) |
O1—Cu—N2 | 85.52 (10) | O1—C1—Kii | 56.75 (14) |
O2iv—K—O3v | 74.43 (6) | C2—C1—Kii | 146.22 (19) |
O2iv—K—O1ii | 115.13 (7) | C1—C2—C3 | 113.3 (2) |
O3v—K—O1ii | 112.62 (6) | C1—C2—H2A | 108.9 |
O2iv—K—N2 | 74.02 (7) | C3—C2—H2A | 108.9 |
O3v—K—N2 | 148.42 (7) | C1—C2—H2B | 108.9 |
O1ii—K—N2 | 80.26 (7) | C3—C2—H2B | 108.9 |
O2iv—K—O3 | 76.18 (6) | H2A—C2—H2B | 107.7 |
O3v—K—O3 | 116.45 (6) | N1—C3—C2 | 111.2 (2) |
O1ii—K—O3 | 130.81 (6) | N1—C3—H3A | 109.4 |
N2—K—O3 | 56.00 (7) | C2—C3—H3A | 109.4 |
O2iv—K—O2ii | 119.10 (6) | N1—C3—H3B | 109.4 |
O3v—K—O2ii | 72.39 (6) | C2—C3—H3B | 109.4 |
O1ii—K—O2ii | 43.53 (6) | H3A—C3—H3B | 108.0 |
N2—K—O2ii | 123.51 (7) | N1—C4—C5 | 126.2 (3) |
O3—K—O2ii | 164.61 (6) | N1—C4—H4 | 116.9 |
O2iv—K—Sii | 138.88 (5) | C5—C4—H4 | 116.9 |
O3v—K—Sii | 137.43 (5) | C10—C5—C6 | 119.4 (3) |
O1ii—K—Sii | 80.14 (5) | C10—C5—C4 | 117.1 (3) |
N2—K—Sii | 71.40 (5) | C6—C5—C4 | 123.5 (3) |
O3—K—Sii | 66.34 (4) | O3—C6—C7 | 118.4 (3) |
O2ii—K—Sii | 98.51 (4) | O3—C6—C5 | 123.9 (3) |
C1ii—K—Sii | 95.62 (5) | C7—C6—C5 | 117.8 (3) |
C6v—K—Sii | 118.23 (6) | O3—C6—Kiii | 50.79 (14) |
C11—S—Kii | 81.76 (10) | C7—C6—Kiii | 90.20 (19) |
C1—O1—Cu | 123.83 (19) | C5—C6—Kiii | 128.55 (19) |
C1—O1—Kii | 100.12 (17) | C8—C7—C6 | 121.1 (3) |
Cu—O1—Kii | 135.91 (10) | C8—C7—H7 | 119.4 |
C1—O2—Kvi | 132.05 (18) | C6—C7—H7 | 119.4 |
C1—O2—Kii | 83.03 (17) | C7—C8—C9 | 121.4 (3) |
Kvi—O2—Kii | 103.12 (6) | C7—C8—H8 | 119.3 |
C6—O3—Cu | 127.12 (19) | C9—C8—H8 | 119.3 |
C6—O3—Kiii | 107.22 (17) | C10—C9—C8 | 118.8 (3) |
Cu—O3—Kiii | 102.22 (8) | C10—C9—H9 | 120.6 |
C6—O3—K | 114.89 (17) | C8—C9—H9 | 120.6 |
Cu—O3—K | 96.03 (8) | C9—C10—C5 | 121.5 (3) |
Kiii—O3—K | 107.50 (7) | C9—C10—H10 | 119.3 |
C4—N1—C3 | 117.9 (3) | C5—C10—H10 | 119.3 |
C4—N1—Cu | 125.3 (2) | N2—C11—S | 179.1 (3) |
C3—N1—Cu | 116.40 (19) | N2—C11—K | 49.80 (17) |
C11—N2—Cu | 139.8 (2) | S—C11—K | 131.07 (14) |
C11—N2—K | 112.4 (2) | ||
Cu—O1—C1—O2 | −145.2 (2) | O1—C1—O2—Cui | 114.9 (2) |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+1, −y+1, −z+1; (iii) −x+3/2, y−1/2, z; (iv) x+1/2, −y+1/2, −z+1; (v) −x+3/2, y+1/2, z; (vi) x−1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | K[Cu(NCS)(C10H9NO3)] |
Mr | 351.90 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 120 |
a, b, c (Å) | 12.5103 (7), 8.4276 (6), 24.401 (2) |
V (Å3) | 2572.6 (3) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 2.19 |
Crystal size (mm) | 0.40 × 0.30 × 0.15 |
Data collection | |
Diffractometer | Kuma KM-4 with a CCD area detector diffractometer |
Absorption correction | Analytical CrysAlis RED (Oxford Diffraction, 2002) |
Tmin, Tmax | 0.444, 0.750 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10607, 2248, 2040 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.080, 1.03 |
No. of reflections | 2248 |
No. of parameters | 172 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.45, −0.42 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2002), CrysAlis RED (Oxford Diffraction, 2002), CrysAlis RED, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEPIII (Johnson & Burnett, 1996), SHELXL97 and PARST (Nardelli, 1995).
Cu—O3 | 1.921 (2) | K—O1ii | 2.742 (2) |
Cu—N1 | 1.950 (3) | K—N2 | 2.895 (3) |
Cu—O1 | 1.965 (2) | K—O3 | 2.938 (2) |
Cu—N2 | 1.999 (3) | K—O2ii | 3.134 (2) |
Cu—O2i | 2.639 (2) | K—Sii | 3.3857 (10) |
Cu—Sii | 2.9771 (8) | S—C11 | 1.635 (3) |
K—O2iii | 2.687 (2) | N2—C11 | 1.159 (4) |
K—O3iv | 2.724 (2) | ||
O3—Cu—N1 | 93.55 (10) | N1—Cu—N2 | 175.43 (10) |
O3—Cu—O1 | 173.66 (9) | O1—Cu—N2 | 85.52 (10) |
N1—Cu—O1 | 92.48 (9) | N2—C11—S | 179.1 (3) |
O3—Cu—N2 | 88.61 (10) | ||
Cu—O1—C1—O2 | −145.2 (2) | O1—C1—O2—Cui | 114.9 (2) |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+1, −y+1, −z+1; (iii) x+1/2, −y+1/2, −z+1; (iv) −x+3/2, y+1/2, z. |
Both thiocyanate and carboxylate groups can act as monodentate, bidentate or one- or three-atom bridging ligands (Mohamed et al., 2000; Zou et al., 1998), forming various types of monomeric, oligomeric or polymeric structures. The coordination mode of these groups has a significant impact on the magnetic and spectral characteristics of their complexes. In addition to the various coordination modes of the carboxylate group, the various bonding arrangements in polynuclear complexes, in particular syn,syn, syn,anti or anti,anti arrangements, significantly alter the whole form of the polymeric structure.
The group of copper(II) Schiff base complexes derived from salicylaldehyde and amino acids contains a number of examples of various coordination modes and arrangements of the carboxylate group. The first coordination mode of the carboxylate group is found in the structure of aqua(N-salicylideneglycinato)copper(II) hemihydrate (Bkouche-Waksman et al., 1988), where Cu-OCO-Cu' bridges are formed in the polymeric chain. Another coordination mode of the carboxylate group is present in the structure of (µ-N-salicylidene-L-valinato)-N-salicylidene-L-valinato-diaquadicopper(II) (Korhonen & Hämelainen, 1979), where one-atom Cu—O—Cu' bridges are formed, probably due to the large volume of the isopropyl group of L-valine.
Considering the arrangement of the bidentate carboxylate group, structures with syn,syn (acetate type) and mostly syn,anti arrangements are formed (Warda, 1997a,b; Wanga et al., 2002). Only a minority of structures from the group of (N-salicylideneamino-acidato)copper(II) complexes display the anti,anti arrangement of the multidentate carboxylate group (Warda et al., 1997; Warda, 1997c,d; Butcher et al., 2003). As reported previously, pseudohalogeno (NCX, where X is O or S) Schiff base cuprates(II) derived from α-alanine (Friebel et al., 1997), DL-phenylalanine (Sivý et al., 1990) and DL-valine (Vančo et al., 2003) display dimeric structures formed by opposite enantiomeric coordination units connected through two linear three-atom pseudohalogeno bridges. The formation of enantiomeric coordination units, however, cannot occur in the case of pseudohalogeno (N-salicylidene-β-alaninato)cuprates(II), and under the influence of this absence the crystal or molecular structures could alter significantly. The first example supporting this assumption was the structure of tetrasodium [bis{(µ-isothiocyanato-N,S)(N-salicylidene-β- alaninato)}dicuprate(II)]dithiocyanate tetrahydrate (Kettmann et al., 1992), with two uncoordinated thiocyanate groups per dimer. As another direct proof of this assumption, we report here the crystal structure of the title compound, (I). \sch
Compound (I) consists of [Cu(sal-β-ala)(NCS)] coordination units (Fig. 1). The CuII ion adopts a distorted tetragonal-bipyramidal geometry, defined by an O,N,O'-tridentate N-salicylidene-β-alanine dianion and the N atom of the NCS− ligand in the basal plane (selected geometric parameters are given in Table 1). The first axial position is occupied by the thiocyanate atom Si from a neighbouring molecule, with a Cu—Si distance of 2.9770 (8) Å [symmetry code: (i) 1 − x, 1 − y, 1 − z]. This is comparable with the average length (3.014 Å) of this bond in related complexes in the Cambridge Structural Database (Version 5.24.3; Allen, 2002). The second axial position is occupied by atom Oii of a bridging carboxylate group from an adjacent coordination unit [symmetry code: (ii) 1 − x, −y, 1 − z]. Thus, [Cu(sal-β-ala)(NCS)]− ions form infinite one-dimensional polymeric polyanions in the [010] direction (Fig. 2). The Cu—O1—C1—O2 and O1—C1—O2—Cuii metal-carboxyl torsion angles are −145.2 (2) and 114.9 (2)°, respectively, indicating an anti,anti arrangement of the bridging carboxylate group.
The mean planes through the Cu atom and the four basal atoms, and through the six-membered phenyl ring A and the chelate ring B (see Scheme), are almost parallel, with the angles between the basal plane and ring A, the basal plane and ring B, and ring A and ring B being 6.75 (9), 3.98 (6) and 3.06 (8)°, respectively. For the six-membered chelate ring C, the Cremer-Pople puckering parameters (Cremer & Pople, 1975) are Q = 0.705 (3) Å, θ = 96.6 (2)° and ϕ2 = 41.8 (2)°, indicating a conformation close to the twisted-boat form.
The crystal packing in (I) is dominated by interactions between the K+ ions and the heteroatoms of neighbouring chains of polyanions, which leads to the formation of two-dimensional nets of molecules parallel to (110). The coordination number of the K+ ion is 7 and its coordination geometry can be described as a distorted pentagonal bipyramid, with atoms Si and O2iii in the apical positions [symmetry code: (iii) 1/2 + x, 1/2 − y, 1 − z].