Iodo-oxyapatite, the first example from a new class of modulated apatites

Iodo-oxyapatite [pentadecacalcium iodide oxide nonaphosphate, Ca₁₅(PO₄)₉IO] was synthesized by a flux method and the structure was solved from single-crystal X-ray data. The crystal structure was refined in the space group P6₃/m [a = 9.567 (1), c = 20.754 (2) Å and Z = 2] to wR on F of 0.0459. Iodo-oxyapatite has a typical hexagonal apatite structure but the unit cell is tripled along the hexad owing to ordering of the iodide and oxide ions along this direction.

Computing details

Figures

(iodo)

Crystal data

[Ca15(PO4)9IO]	Dx = 3.227 Mg m^−3
Mr = 1598.8	Mo Kα radiation, λ = 0.7107 Å
Hexagonal, P63/m	Cell parameters from 5000 reflections
a = 9.567 (1) Å	θ = 2.0–23.9°
c = 20.754 (2) Å	µ = 3.89 mm^−1
V = 1645.07 Å^3	T = 293 K
Z = 2	Hexagonal rod, colourless
F(000) = 1568	0.18 × 0.03 × 0.03 mm

Data collection

STOE IPDS diffractometer	419 reflections with I > 2σ(I)
phi rotation scans	Rint = 0.084
Absorption correction: numerical from crystal shape ?	θmax = 23.9°, θmin = 2.0°
Tmin = 0.859, Tmax = 0.917	h = −8→0
878 measured reflections	k = 0→10
878 independent reflections	l = 0→23

Refinement

Refinement on F	72 parameters
R[F^2 > 2σ(F^2)] = 0.045	w = 1/(σ^2(F) + 0.0004F^2)
wR(F^2) = 0.055	(Δ/σ)max = 0.0001
S = 1.01	Δρmax = 2.50 e Å^−3
878 reflections	Δρmin = −2.48 e Å^−3

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
O(11)	0.473 (1)	0.590 (1)	0.25	0.028 (3)
O(12)	0.4599 (9)	0.5848 (8)	0.5930 (5)	0.028 (3)
O(21)	0.481 (1)	0.328 (1)	0.25	0.010 (2)
O(22)	0.4886 (8)	0.3353 (8)	0.5830 (4)	0.010 (2)
O(31)	0.268 (1)	0.360 (1)	0.1901 (5)	0.034 (2)
O(32)	0.2831 (9)	0.375 (1)	0.5186 (4)	0.034 (2)
O(33)	0.245 (1)	0.318 (1)	0.8634 (5)	0.034 (2)
P(11)	0.3731 (5)	0.4048 (5)	0.25	0.0063 (7)
P(12)	0.3690 (3)	0.3999 (3)	0.5826 (2)	0.0063 (7)
Ca(11)	0.333333	0.666667	0.1665 (2)	0.0103 (5)
Ca(12)	0.333333	0.666667	0.5008 (3)	0.0103 (5)
Ca(13)	0.333333	0.666667	0.8297 (2)	0.0103 (5)
Ca(21)	0.2435 (5)	0.0041 (4)	0.25	0.028 (2)
Ca(22)	0.2765 (3)	0.0144 (3)	0.5859 (1)	0.018 (1)
I(11)	0	0	0	0.0211 (9)	0.7 (1)
I(12)	0	0	0.1716 (6)	0.0211 (9)	0.174 (3)
O(41)	0	0	0.237 (3)	0.0211 (9)	0.35 (2)
O(42)	0	0	0.384 (6)	0.0211 (9)	0.14 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O(11)	0.017 (3)	0.010 (3)	0.060 (6)	0.008 (2)	0	0
O(12)	0.017 (3)	0.010 (3)	0.060 (6)	0.008 (2)	0	0
O(21)	0.012 (2)	0.015 (2)	0.011 (3)	0.011 (2)	0	0
O(22)	0.012 (2)	0.015 (2)	0.011 (3)	0.011 (2)	0	0
O(31)	0.029 (2)	0.055 (3)	0.034 (3)	0.033 (3)	−0.021 (2)	−0.029 (3)
O(32)	0.029 (2)	0.055 (3)	0.034 (3)	0.033 (3)	−0.021 (2)	−0.029 (3)
O(33)	0.029 (2)	0.055 (3)	0.034 (3)	0.033 (3)	−0.021 (2)	−0.029 (3)
P(11)	0.0063 (9)	0.0078 (9)	0.008 (1)	0.0056 (7)	0	0
P(12)	0.0063 (9)	0.0078 (9)	0.008 (1)	0.0056 (7)	0	0
Ca(11)	0.0114 (6)	0.0114 (6)	0.008 (1)	0.0057 (3)	0	0
Ca(12)	0.0114 (6)	0.0114 (6)	0.008 (1)	0.0057 (3)	0	0
Ca(13)	0.0114 (6)	0.0114 (6)	0.008 (1)	0.0057 (3)	0	0
Ca(21)	0.052 (3)	0.010 (2)	0.017 (2)	0.012 (2)	0	0
Ca(22)	0.025 (1)	0.015 (1)	0.012 (1)	0.008 (1)	0.001 (1)	0.002 (1)
I(11)	0.0033 (8)	0.0033 (8)	0.057 (2)	0.0016 (4)	0	0
I(12)	0.0033 (8)	0.0033 (8)	0.057 (2)	0.0016 (4)	0	0
O(41)	0.0033 (8)	0.0033 (8)	0.057 (2)	0.0016 (4)	0	0
O(42)	0.0033 (8)	0.0033 (8)	0.057 (2)	0.0016 (4)	0	0

Geometric parameters (Å, º)

P(11)—O(11)	1.53 (1)	Ca(12)—O(32)^viii	2.61 (1)
P(11)—O(21)	1.54 (2)	Ca(13)—O(12)^xii	2.37 (1)
P(11)—O(31)	1.52 (1)	Ca(13)—O(12)^ii	2.37 (1)
P(11)—O(31)^i	1.52 (1)	Ca(13)—O(12)^xiii	2.37 (1)
P(12)—O(12)	1.547 (7)	Ca(13)—O(21)^ix	2.41 (1)
P(12)—O(22)	1.548 (9)	Ca(13)—O(21)^xiv	2.407 (8)
P(12)—O(32)	1.52 (1)	Ca(13)—O(21)^x	2.41 (1)
P(12)—O(33)^ii	1.53 (1)	Ca(21)—O(11)^xv	2.39 (2)
Ca(11)—O(11)	2.51 (1)	Ca(21)—O(21)	2.781 (9)
Ca(11)—O(11)^iii	2.51 (1)	Ca(21)—O(31)^xvi	2.577 (9)
Ca(11)—O(11)^iv	2.51 (1)	Ca(21)—O(31)^xvii	2.577 (9)
Ca(11)—O(22)^v	2.438 (9)	Ca(21)—O(33)^xviii	2.45 (1)
Ca(11)—O(22)^vi	2.438 (9)	Ca(21)—O(33)^xix	2.45 (1)
Ca(11)—O(22)^vii	2.44 (1)	Ca(21)—I(12)	2.825 (8)
Ca(11)—O(31)	2.72 (1)	Ca(21)—I(12)^xvi	2.825 (8)
Ca(11)—O(31)^iv	2.718 (9)	Ca(21)—O(41)	2.326 (8)
Ca(11)—O(31)^viii	2.72 (2)	Ca(21)—O(41)^xvi	2.326 (8)
Ca(12)—O(12)	2.59 (1)	Ca(22)—O(12)^xv	2.31 (1)
Ca(12)—O(12)^iv	2.59 (1)	Ca(22)—O(22)	2.705 (6)
Ca(12)—O(12)^viii	2.59 (1)	Ca(22)—O(31)^xx	2.30 (1)
Ca(12)—O(22)^ix	2.44 (1)	Ca(22)—O(32)^xviii	2.334 (9)
Ca(12)—O(22)^x	2.44 (1)	Ca(22)—O(32)^xvii	2.853 (8)
Ca(12)—O(22)^xi	2.441 (9)	Ca(22)—O(33)^xxi	2.495 (9)
Ca(12)—O(32)	2.61 (1)	Ca(22)—O(42)^xxii	2.65 (3)
Ca(12)—O(32)^iv	2.609 (8)
O(11)—P(11)—O(21)	111.7 (7)	O(32)—Ca(12)—O(32)^viii	118.0 (3)
O(11)—P(11)—O(31)	105.5 (5)	O(32)^iv—Ca(12)—O(32)	118.0 (4)
O(11)—P(11)—O(31)^i	105.5 (5)	O(32)^iv—Ca(12)—O(32)^viii	118.0 (4)
O(21)—P(11)—O(31)	112.1 (5)	O(32)^viii—Ca(12)—O(32)	118.0 (3)
O(21)—P(11)—O(31)^i	112.1 (5)	O(32)^viii—Ca(12)—O(32)^iv	118.0 (4)
O(31)—P(11)—O(31)^i	109.6 (6)	O(12)^xii—Ca(13)—O(12)^ii	79.1 (4)
O(31)^i—P(11)—O(31)	109.6 (6)	O(12)^xii—Ca(13)—O(12)^xiii	79.1 (3)
O(12)—P(12)—O(22)	110.5 (4)	O(12)^xii—Ca(13)—O(21)^ix	154.1 (3)
O(12)—P(12)—O(32)	104.6 (6)	O(12)^xii—Ca(13)—O(21)^xiv	88.8 (3)
O(12)—P(12)—O(33)^ii	109.3 (6)	O(12)^xii—Ca(13)—O(21)^x	121.2 (4)
O(22)—P(12)—O(32)	113.1 (6)	O(12)^ii—Ca(13)—O(12)^xii	79.1 (4)
O(22)—P(12)—O(33)^ii	109.3 (6)	O(12)^ii—Ca(13)—O(12)^xiii	79.1 (4)
O(32)—P(12)—O(33)^ii	109.9 (5)	O(12)^ii—Ca(13)—O(21)^ix	88.8 (3)
O(11)—Ca(11)—O(11)^iii	77.7 (4)	O(12)^ii—Ca(13)—O(21)^xiv	121.2 (4)
O(11)—Ca(11)—O(11)^iv	77.7 (4)	O(12)^ii—Ca(13)—O(21)^x	154.1 (3)
O(11)—Ca(11)—O(22)^v	125.4 (3)	O(12)^xiii—Ca(13)—O(12)^xii	79.1 (3)
O(11)—Ca(11)—O(22)^vi	90.7 (3)	O(12)^xiii—Ca(13)—O(12)^ii	79.1 (4)
O(11)—Ca(11)—O(22)^vii	151.6 (3)	O(12)^xiii—Ca(13)—O(21)^ix	121.2 (3)
O(11)—Ca(11)—O(31)	55.2 (3)	O(12)^xiii—Ca(13)—O(21)^xiv	154.1 (5)
O(11)—Ca(11)—O(31)^iv	67.5 (4)	O(12)^xiii—Ca(13)—O(21)^x	88.8 (4)
O(11)—Ca(11)—O(31)^viii	125.4 (4)	O(21)^ix—Ca(13)—O(21)^xiv	78.0 (4)
O(11)^iii—Ca(11)—O(11)	77.7 (4)	O(21)^ix—Ca(13)—O(21)^x	78.0 (4)
O(11)^iii—Ca(11)—O(11)^iv	77.7 (3)	O(21)^xiv—Ca(13)—O(21)^ix	78.0 (4)
O(11)^iii—Ca(11)—O(22)^v	90.7 (3)	O(21)^xiv—Ca(13)—O(21)^x	78.0 (4)
O(11)^iii—Ca(11)—O(22)^vi	151.6 (4)	O(21)^x—Ca(13)—O(21)^ix	78.0 (4)
O(11)^iii—Ca(11)—O(22)^vii	125.4 (4)	O(21)^x—Ca(13)—O(21)^xiv	78.0 (4)
O(11)^iii—Ca(11)—O(31)	67.5 (4)	O(11)^xv—Ca(21)—O(21)	99.6 (4)
O(11)^iii—Ca(11)—O(31)^iv	125.4 (3)	O(11)^xv—Ca(21)—O(31)^xvi	71.6 (4)
O(11)^iii—Ca(11)—O(31)^viii	55.2 (5)	O(11)^xv—Ca(21)—O(31)^xvii	71.6 (4)
O(11)^iv—Ca(11)—O(11)	77.7 (4)	O(11)^xv—Ca(21)—O(33)^xviii	87.4 (4)
O(11)^iv—Ca(11)—O(11)^iii	77.7 (3)	O(11)^xv—Ca(21)—O(33)^xix	87.4 (4)
O(11)^iv—Ca(11)—O(22)^v	151.6 (4)	O(11)^xv—Ca(21)—I(12)	137.5 (2)
O(11)^iv—Ca(11)—O(22)^vi	125.4 (3)	O(11)^xv—Ca(21)—I(12)^xvi	137.5 (2)
O(11)^iv—Ca(11)—O(22)^vii	90.7 (4)	O(11)^xv—Ca(21)—O(41)	153.6 (4)
O(11)^iv—Ca(11)—O(31)	125.4 (4)	O(11)^xv—Ca(21)—O(41)^xvi	153.6 (4)
O(11)^iv—Ca(11)—O(31)^iv	55.2 (4)	O(21)—Ca(21)—O(31)^xvi	149.2 (3)
O(11)^iv—Ca(11)—O(31)^viii	67.5 (4)	O(21)—Ca(21)—O(31)^xvii	149.2 (3)
O(22)^v—Ca(11)—O(22)^vi	75.0 (3)	O(21)—Ca(21)—O(33)^xviii	74.6 (3)
O(22)^v—Ca(11)—O(22)^vii	75.0 (3)	O(21)—Ca(21)—O(33)^xix	74.6 (3)
O(22)^v—Ca(11)—O(31)	70.9 (3)	O(21)—Ca(21)—I(12)	103.0 (3)
O(22)^v—Ca(11)—O(31)^iv	143.7 (3)	O(21)—Ca(21)—I(12)^xvi	103.0 (3)
O(22)^v—Ca(11)—O(31)^viii	84.5 (3)	O(21)—Ca(21)—O(41)	105.9 (3)
O(22)^vi—Ca(11)—O(22)^v	75.0 (3)	O(21)—Ca(21)—O(41)^xvi	105.9 (3)
O(22)^vi—Ca(11)—O(22)^vii	75.0 (3)	O(31)^xvi—Ca(21)—O(31)^xvii	57.7 (3)
O(22)^vi—Ca(11)—O(31)	84.5 (3)	O(31)^xvi—Ca(21)—O(33)^xviii	132.4 (4)
O(22)^vi—Ca(11)—O(31)^iv	70.9 (3)	O(31)^xvi—Ca(21)—O(33)^xix	75.5 (4)
O(22)^vi—Ca(11)—O(31)^viii	143.7 (3)	O(31)^xvi—Ca(21)—I(12)	102.8 (3)
O(22)^vii—Ca(11)—O(22)^v	75.0 (3)	O(31)^xvi—Ca(21)—I(12)^xvi	70.5 (3)
O(22)^vii—Ca(11)—O(22)^vi	75.0 (3)	O(31)^xvi—Ca(21)—O(41)	89.3 (8)
O(22)^vii—Ca(11)—O(31)	143.7 (3)	O(31)^xvi—Ca(21)—O(41)^xvi	82.9 (8)
O(22)^vii—Ca(11)—O(31)^iv	84.5 (3)	O(31)^xvii—Ca(21)—O(31)^xvi	57.7 (3)
O(22)^vii—Ca(11)—O(31)^viii	70.9 (3)	O(31)^xvii—Ca(21)—O(33)^xviii	75.5 (4)
O(31)—Ca(11)—O(31)^iv	116.8 (4)	O(31)^xvii—Ca(21)—O(33)^xix	132.4 (4)
O(31)—Ca(11)—O(31)^viii	116.8 (3)	O(31)^xvii—Ca(21)—I(12)	70.5 (3)
O(31)^iv—Ca(11)—O(31)	116.8 (4)	O(31)^xvii—Ca(21)—I(12)^xvi	102.8 (3)
O(31)^iv—Ca(11)—O(31)^viii	116.8 (4)	O(31)^xvii—Ca(21)—O(41)	82.9 (8)
O(31)^viii—Ca(11)—O(31)	116.8 (3)	O(31)^xvii—Ca(21)—O(41)^xvi	89.3 (8)
O(31)^viii—Ca(11)—O(31)^iv	116.8 (4)	O(33)^xviii—Ca(21)—O(33)^xix	147.4 (3)
O(12)—Ca(12)—O(12)^iv	71.3 (3)	O(33)^xviii—Ca(21)—I(12)	65.1 (3)
O(12)—Ca(12)—O(12)^viii	71.3 (3)	O(33)^xviii—Ca(21)—I(12)^xvi	133.1 (4)
O(12)—Ca(12)—O(22)^ix	95.2 (3)	O(33)^xviii—Ca(21)—O(41)	93 (1)
O(12)—Ca(12)—O(22)^x	154.3 (2)	O(33)^xviii—Ca(21)—O(41)^xvi	106 (1)
O(12)—Ca(12)—O(22)^xi	126.1 (3)	O(33)^xix—Ca(21)—O(33)^xviii	147.4 (3)
O(12)—Ca(12)—O(32)	55.6 (3)	O(33)^xix—Ca(21)—I(12)	133.1 (4)
O(12)—Ca(12)—O(32)^iv	73.0 (3)	O(33)^xix—Ca(21)—I(12)^xvi	65.1 (3)
O(12)—Ca(12)—O(32)^viii	122.8 (3)	O(33)^xix—Ca(21)—O(41)	106 (1)
O(12)^iv—Ca(12)—O(12)	71.3 (3)	O(33)^xix—Ca(21)—O(41)^xvi	93 (1)
O(12)^iv—Ca(12)—O(12)^viii	71.3 (3)	I(12)—Ca(21)—I(12)^xvi	70.3 (3)
O(12)^iv—Ca(12)—O(22)^ix	126.1 (2)	I(12)—Ca(21)—O(41)	29 (1)
O(12)^iv—Ca(12)—O(22)^x	95.2 (3)	I(12)—Ca(21)—O(41)^xvi	42 (1)
O(12)^iv—Ca(12)—O(22)^xi	154.3 (3)	I(12)^xvi—Ca(21)—I(12)	70.3 (3)
O(12)^iv—Ca(12)—O(32)	122.8 (4)	I(12)^xvi—Ca(21)—O(41)	42 (1)
O(12)^iv—Ca(12)—O(32)^iv	55.6 (3)	I(12)^xvi—Ca(21)—O(41)^xvi	29 (1)
O(12)^iv—Ca(12)—O(32)^viii	73.0 (3)	O(41)—Ca(21)—O(41)^xvi	13 (2)
O(12)^viii—Ca(12)—O(12)	71.3 (3)	O(41)^xvi—Ca(21)—O(41)	13 (2)
O(12)^viii—Ca(12)—O(12)^iv	71.3 (3)	O(12)^xv—Ca(22)—O(22)	109.6 (3)
O(12)^viii—Ca(12)—O(22)^ix	154.3 (3)	O(12)^xv—Ca(22)—O(31)^xx	85.4 (5)
O(12)^viii—Ca(12)—O(22)^x	126.1 (3)	O(12)^xv—Ca(22)—O(32)^xviii	89.2 (4)
O(12)^viii—Ca(12)—O(22)^xi	95.2 (3)	O(12)^xv—Ca(22)—O(32)^xvii	72.7 (4)
O(12)^viii—Ca(12)—O(32)	73.0 (3)	O(12)^xv—Ca(22)—O(33)^xxi	77.7 (4)
O(12)^viii—Ca(12)—O(32)^iv	122.8 (3)	O(12)^xv—Ca(22)—O(42)^xxii	143 (1)
O(12)^viii—Ca(12)—O(32)^viii	55.6 (3)	O(22)—Ca(22)—O(31)^xx	73.2 (3)
O(22)^ix—Ca(12)—O(22)^x	74.9 (3)	O(22)—Ca(22)—O(32)^xviii	70.3 (3)
O(22)^ix—Ca(12)—O(22)^xi	74.9 (3)	O(22)—Ca(22)—O(32)^xvii	149.3 (3)
O(22)^ix—Ca(12)—O(32)	81.3 (3)	O(22)—Ca(22)—O(33)^xxi	155.2 (3)
O(22)^ix—Ca(12)—O(32)^iv	70.5 (3)	O(22)—Ca(22)—O(42)^xxii	103.1 (2)
O(22)^ix—Ca(12)—O(32)^viii	142.0 (4)	O(31)^xx—Ca(22)—O(32)^xviii	138.7 (3)
O(22)^x—Ca(12)—O(22)^ix	74.9 (3)	O(31)^xx—Ca(22)—O(32)^xvii	136.6 (4)
O(22)^x—Ca(12)—O(22)^xi	74.9 (3)	O(31)^xx—Ca(22)—O(33)^xxi	84.2 (4)
O(22)^x—Ca(12)—O(32)	142.0 (4)	O(31)^xx—Ca(22)—O(42)^xxii	89 (2)
O(22)^x—Ca(12)—O(32)^iv	81.3 (3)	O(32)^xviii—Ca(22)—O(32)^xvii	79.2 (3)
O(22)^x—Ca(12)—O(32)^viii	70.5 (3)	O(32)^xviii—Ca(22)—O(33)^xxi	134.3 (4)
O(22)^xi—Ca(12)—O(22)^ix	74.9 (3)	O(32)^xviii—Ca(22)—O(42)^xxii	118 (2)
O(22)^xi—Ca(12)—O(22)^x	74.9 (3)	O(32)^xvii—Ca(22)—O(32)^xviii	79.2 (3)
O(22)^xi—Ca(12)—O(32)	70.5 (3)	O(32)^xvii—Ca(22)—O(33)^xxi	55.1 (3)
O(22)^xi—Ca(12)—O(32)^iv	142.0 (3)	O(32)^xvii—Ca(22)—O(42)^xxii	88 (1)
O(22)^xi—Ca(12)—O(32)^viii	81.3 (3)	O(33)^xxi—Ca(22)—O(42)^xxii	66 (1)
O(32)—Ca(12)—O(32)^iv	118.0 (4)

Symmetry codes: (i) x, y, −z+1/2; (ii) x, y, −z+3/2; (iii) −x+y, −x+1, −z+1/2; (iv) −y+1, x−y+1, z; (v) x−y, x, z−1/2; (vi) −x+1, −y+1, z−1/2; (vii) y, −x+y+1, z−1/2; (viii) −x+y, −x+1, z; (ix) −x+1, −y+1, −z+1; (x) y, −x+y+1, −z+1; (xi) x−y, x, −z+1; (xii) −x+y, −x+1, −z+3/2; (xiii) −y+1, x−y+1, −z+3/2; (xiv) x−y, x, z+1/2; (xv) −y+1, x−y, z; (xvi) −x+y, −x, −z+1/2; (xvii) −x+y, −x, z; (xviii) y, −x+y, −z+1; (xix) y, −x+y, z−1/2; (xx) y, −x+y, z+1/2; (xxi) −x+y, −x, −z+3/2; (xxii) −x, −y, −z+1.