Solid-state transformation of 4,2′-an­hydro-5-(β-D-arabino­furan­osyl)­uracil dihydrate to 4,2′-an­hydro-5-(β-D-arabino­furan­osyl)­uracil mono­hydrate

Crystals of 4,2′-an­hydro-5-(β-D-arabino­furan­osyl)­uracil, (I), obtained from an aqueous solution, were characterized as the dihydrate, C₉H₁₀N₂O₅·2H₂O, (Ia). In air, these crystals slowly transform to the mono­hydrate, C₉H₁₀N₂O₅·H₂O, (Ib), but remain crystalline. The solid-state transformation proceeds with the loss of one water mol­ecule and a rearrangement of hydrogen-bonded layers of mol­ecules. The furan­ose ring in (I) has an approximate C4′-exo,O4′-endo twist conformation. The central five-membered ring is slightly puckered. The uracil group is planar within experimental uncertainty.

Computing details

For both compounds, data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 1996); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL; software used to prepare material for publication: CIF in SHELXL97.

(Ia) 4,2'-Anhydro-5-(β-D-arabinofuranosyl)-uracil dihydrate

Crystal data

C9H10N2O5·2H2O	F(000) = 276
Mr = 262.22	Dx = 1.549 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 6.0315 (7) Å	Cell parameters from 207 reflections
b = 7.2490 (8) Å	θ = 3–23°
c = 12.8693 (19) Å	µ = 0.14 mm^−1
β = 91.921 (9)°	T = 135 K
V = 562.36 (12) Å^3	Block, colorless
Z = 2	0.60 × 0.54 × 0.34 mm

Data collection

Siemens_SMART diffractometer	1970 independent reflections
Radiation source: normal-focus sealed tube	1942 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
ω scans	θmax = 32.3°, θmin = 1.6°
Absorption correction: numerical (SHELXTL; sheldrick, 1996)	h = −8→8
Tmin = 0.916, Tmax = 0.961	k = −9→10
10536 measured reflections	l = −17→19

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.025	All H-atom parameters refined
wR(F^2) = 0.076	w = 1/[σ^2(Fo^2) + (0.05P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.38	(Δ/σ)max < 0.001
1970 reflections	Δρmax = 0.31 e Å^−3
220 parameters	Δρmin = −0.27 e Å^−3
1 restraint	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.31 (2)

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.

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

	x	y	z	Uiso*/Ueq
O4	0.51583 (11)	0.04216 (15)	0.12081 (5)	0.01925 (17)
O3'	0.54763 (12)	0.07751 (11)	0.38795 (6)	0.01560 (16)
O2	0.32296 (12)	0.08300 (12)	−0.22573 (6)	0.01750 (17)
O4'	0.07803 (12)	0.20057 (12)	0.22666 (6)	0.01488 (16)
O5'	0.24383 (11)	0.55290 (11)	0.26988 (6)	0.01481 (15)
O7	0.73319 (15)	0.33605 (14)	0.50065 (7)	0.0237 (2)
O8	0.87328 (15)	−0.19923 (15)	0.38915 (8)	0.0269 (2)
N3	0.43995 (13)	0.06573 (16)	−0.05461 (6)	0.01728 (19)
N1	0.05786 (12)	0.05147 (15)	−0.10669 (6)	0.01471 (17)
C5	0.14705 (14)	0.03136 (15)	0.07033 (7)	0.01359 (18)
C1'	0.14462 (15)	0.02506 (15)	0.18590 (7)	0.01374 (18)
C2'	0.39391 (16)	0.00618 (14)	0.21572 (7)	0.01415 (18)
C4	0.36934 (14)	0.04718 (16)	0.03989 (7)	0.01440 (18)
C3'	0.44064 (15)	0.15504 (14)	0.29785 (7)	0.01272 (17)
C2	0.27836 (15)	0.06767 (15)	−0.13220 (7)	0.01375 (18)
C4'	0.20713 (15)	0.22824 (14)	0.32095 (7)	0.01268 (17)
C5'	0.19396 (17)	0.42956 (15)	0.35201 (7)	0.01447 (18)
C6	−0.00968 (16)	0.03286 (17)	−0.00785 (8)	0.01563 (19)
H1'	0.068 (3)	−0.071 (3)	0.2142 (15)	0.024 (4)*
H2'	0.434 (3)	−0.120 (3)	0.2418 (13)	0.015 (4)*
H3'	0.534 (2)	0.251 (3)	0.2706 (12)	0.012 (3)*
H03'	0.607 (3)	0.166 (4)	0.4247 (14)	0.035 (5)*
H4'	0.149 (3)	0.152 (3)	0.3787 (15)	0.028 (5)*
H01	−0.035 (2)	0.049 (3)	−0.1579 (12)	0.015 (3)*
H5'B	0.045 (3)	0.460 (3)	0.3735 (13)	0.018 (4)*
H5'A	0.290 (2)	0.452 (2)	0.4128 (12)	0.010 (3)*
H05'	0.394 (3)	0.548 (4)	0.2608 (14)	0.028 (4)*
H6	−0.156 (3)	0.023 (3)	−0.0006 (13)	0.020 (4)*
H07B	0.655 (4)	0.403 (4)	0.5295 (17)	0.041 (6)*
H07A	0.845 (5)	0.329 (5)	0.530 (2)	0.060 (7)*
H08A	0.785 (4)	−0.112 (4)	0.3901 (15)	0.033 (5)*
H08B	0.839 (3)	−0.275 (3)	0.3434 (16)	0.027 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O4	0.0105 (3)	0.0353 (4)	0.0118 (3)	0.0043 (3)	−0.0006 (2)	−0.0022 (3)
O3'	0.0172 (3)	0.0148 (4)	0.0144 (3)	0.0023 (3)	−0.0051 (2)	−0.0010 (3)
O2	0.0154 (3)	0.0248 (4)	0.0123 (3)	−0.0006 (3)	0.0006 (2)	0.0004 (3)
O4'	0.0133 (3)	0.0167 (3)	0.0144 (3)	0.0036 (3)	−0.0021 (2)	−0.0034 (3)
O5'	0.0133 (3)	0.0154 (3)	0.0156 (3)	0.0013 (3)	−0.0008 (2)	0.0035 (3)
O7	0.0205 (4)	0.0246 (4)	0.0255 (4)	0.0018 (3)	−0.0065 (3)	−0.0094 (4)
O8	0.0211 (4)	0.0255 (5)	0.0333 (4)	0.0097 (3)	−0.0091 (3)	−0.0103 (4)
N3	0.0109 (3)	0.0286 (5)	0.0123 (3)	0.0004 (3)	−0.0003 (2)	−0.0008 (4)
N1	0.0109 (3)	0.0195 (4)	0.0136 (3)	−0.0006 (3)	−0.0015 (2)	−0.0026 (3)
C5	0.0115 (3)	0.0169 (4)	0.0124 (3)	−0.0017 (3)	0.0005 (3)	−0.0022 (3)
C1'	0.0139 (3)	0.0146 (4)	0.0127 (3)	−0.0008 (3)	0.0007 (3)	−0.0015 (3)
C2'	0.0149 (4)	0.0155 (4)	0.0120 (3)	0.0033 (3)	0.0002 (3)	−0.0008 (3)
C4	0.0101 (3)	0.0193 (4)	0.0137 (4)	0.0021 (3)	−0.0011 (3)	−0.0021 (4)
C3'	0.0131 (4)	0.0120 (4)	0.0129 (3)	0.0019 (3)	−0.0009 (3)	−0.0002 (3)
C2	0.0114 (3)	0.0161 (5)	0.0137 (4)	0.0005 (3)	−0.0005 (3)	−0.0015 (4)
C4'	0.0123 (3)	0.0140 (4)	0.0117 (4)	0.0022 (3)	−0.0006 (3)	−0.0004 (3)
C5'	0.0175 (4)	0.0136 (4)	0.0124 (4)	0.0032 (3)	0.0008 (3)	−0.0001 (3)
C6	0.0107 (3)	0.0207 (5)	0.0155 (4)	−0.0022 (4)	0.0009 (3)	−0.0035 (4)

Geometric parameters (Å, º)

O4—C4	1.3434 (11)	N1—C6	1.3554 (12)
O4—C2'	1.4699 (11)	N1—C2	1.3855 (11)
O3'—C3'	1.4237 (11)	C5—C6	1.3573 (12)
O2—C2	1.2470 (11)	C5—C4	1.4140 (12)
O4'—C4'	1.4338 (11)	C5—C1'	1.4886 (13)
O4'—C1'	1.4384 (13)	C1'—C2'	1.5453 (14)
O5'—C5'	1.4243 (12)	C2'—C3'	1.5301 (14)
N3—C4	1.3089 (12)	C3'—C4'	1.5433 (13)
N3—C2	1.3719 (11)	C4'—C5'	1.5159 (14)
C4—O4—C2'	108.33 (7)	N3—C4—C5	127.36 (8)
C4'—O4'—C1'	106.38 (7)	O4—C4—C5	112.84 (8)
C4—N3—C2	115.60 (8)	O3'—C3'—C2'	110.62 (8)
C6—N1—C2	123.50 (8)	O3'—C3'—C4'	111.75 (8)
C6—C5—C4	115.93 (8)	C2'—C3'—C4'	103.15 (8)
C6—C5—C1'	135.31 (8)	O2—C2—N3	122.17 (8)
C4—C5—C1'	108.69 (8)	O2—C2—N1	118.43 (8)
O4'—C1'—C5	110.45 (8)	N3—C2—N1	119.40 (8)
O4'—C1'—C2'	105.61 (8)	O4'—C4'—C5'	109.03 (8)
C5—C1'—C2'	102.04 (7)	O4'—C4'—C3'	105.19 (7)
O4—C2'—C3'	111.29 (8)	C5'—C4'—C3'	115.98 (8)
O4—C2'—C1'	106.72 (7)	O5'—C5'—C4'	113.23 (8)
C3'—C2'—C1'	105.32 (8)	N1—C6—C5	118.21 (8)
N3—C4—O4	119.80 (8)
C4'—O4'—C1'—C5	−143.17 (8)	O4—C2'—C3'—O3'	−116.80 (8)
C4'—O4'—C1'—C2'	−33.57 (10)	C1'—C2'—C3'—O3'	127.93 (8)
C6—C5—C1'—O4'	−74.03 (16)	O4—C2'—C3'—C4'	123.57 (8)
C4—C5—C1'—O4'	102.78 (10)	C1'—C2'—C3'—C4'	8.30 (9)
C6—C5—C1'—C2'	174.06 (13)	C4—N3—C2—O2	−179.41 (11)
C4—C5—C1'—C2'	−9.14 (11)	C4—N3—C2—N1	0.34 (16)
C4—O4—C2'—C3'	−124.69 (9)	C6—N1—C2—O2	179.55 (11)
C4—O4—C2'—C1'	−10.29 (12)	C6—N1—C2—N3	−0.21 (17)
O4'—C1'—C2'—O4	−103.94 (9)	C1'—O4'—C4'—C5'	164.36 (8)
C5—C1'—C2'—O4	11.57 (11)	C1'—O4'—C4'—C3'	39.35 (9)
O4'—C1'—C2'—C3'	14.45 (10)	O3'—C3'—C4'—O4'	−147.44 (8)
C5—C1'—C2'—C3'	129.95 (8)	C2'—C3'—C4'—O4'	−28.59 (9)
C2—N3—C4—O4	179.41 (10)	O3'—C3'—C4'—C5'	92.01 (10)
C2—N3—C4—C5	−0.82 (19)	C2'—C3'—C4'—C5'	−149.14 (8)
C2'—O4—C4—N3	−175.65 (11)	O4'—C4'—C5'—O5'	−51.00 (10)
C2'—O4—C4—C5	4.55 (13)	C3'—C4'—C5'—O5'	67.46 (10)
C6—C5—C4—N3	1.09 (19)	C2—N1—C6—C5	0.49 (18)
C1'—C5—C4—N3	−176.41 (12)	C4—C5—C6—N1	−0.84 (16)
C6—C5—C4—O4	−179.13 (10)	C1'—C5—C6—N1	175.80 (12)
C1'—C5—C4—O4	3.37 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3′—H03′···O7	0.87 (2)	1.73 (2)	2.600 (1)	178 (2)
O5′—H05′···O2^i	0.92 (2)	1.80 (2)	2.701 (1)	167 (2)
N1—H01···O5′^ii	0.85 (2)	1.88 (2)	2.732 (1)	178 (2)
O7—H07A···O8^iii	0.76 (3)	1.97 (3)	2.736 (1)	177 (3)
O7—H07B···O3′^iv	0.78 (3)	2.08 (3)	2.855 (1)	178 (2)
O8—H08A···O3′	0.83 (3)	1.98 (3)	2.807 (1)	174 (3)
O8—H08B···O2^v	0.83 (2)	2.05 (2)	2.855 (1)	164 (2)
C2′—H2′···O2^v	1.00 (2)	2.62 (2)	3.511 (1)	149 (2)
C3′—H3′···O2^i	0.97 (2)	2.63 (2)	3.551 (1)	159 (2)
C6—H6···O4^vi	0.89 (2)	2.57 (2)	3.355 (1)	148 (2)
C6—H6···N3^vi	0.89 (2)	2.53 (2)	3.362 (1)	155 (2)

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

(Ib) 4,2'-Anhydro-5-(β-D-arabinofuranosyl)-uracil monohydrate

Crystal data

C9H10N2O5·H2O	F(000) = 256
Mr = 244.21	Dx = 1.540 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 6.024 (2) Å	Cell parameters from 54 reflections
b = 7.218 (3) Å	θ = 3–23°
c = 12.357 (4) Å	µ = 0.13 mm^−1
β = 101.40 (4)°	T = 137 K
V = 526.7 (3) Å^3	Rod, colorless
Z = 2	0.56 × 0.35 × 0.07 mm

Data collection

Siemens_SMART diffractometer	1808 independent reflections
Radiation source: normal-focus sealed tube	1443 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.109
ω scans	θmax = 32.0°, θmin = 1.7°
Absorption correction: numerical (SHELXTL; sheldrick, 1996)	h = −8→8
Tmin = 0.946, Tmax = 0.991	k = −10→10
10608 measured reflections	l = −18→17

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)] = 0.054	Hydrogen site location: difference Fourier map
wR(F^2) = 0.110	All H atom parameters refined
S = 1.38	w = 1/[σ^2(Fo^2) + (0.04P)^2] where P = (Fo^2 + 2Fc^2)/3
1808 reflections	(Δ/σ)max = 0.001
202 parameters	Δρmax = 0.43 e Å^−3
1 restraint	Δρmin = −0.34 e Å^−3

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.

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

	x	y	z	Uiso*/Ueq
O4	0.4691 (3)	0.9064 (3)	0.87753 (14)	0.0244 (4)
O4'	−0.0308 (4)	0.7577 (2)	0.76255 (15)	0.0211 (4)
O2	0.4446 (3)	0.8582 (3)	1.24412 (14)	0.0221 (4)
N1	0.1218 (4)	0.8988 (3)	1.11709 (18)	0.0194 (4)
C4	0.3619 (4)	0.9015 (4)	0.96299 (19)	0.0182 (5)
O5'	0.0949 (3)	0.3985 (3)	0.70732 (14)	0.0218 (4)
O3'	0.3844 (4)	0.8541 (3)	0.59891 (16)	0.0281 (5)
N3	0.4782 (4)	0.8798 (3)	1.06380 (17)	0.0216 (5)
C5	0.1256 (4)	0.9224 (3)	0.9298 (2)	0.0182 (5)
C2	0.3536 (4)	0.8776 (3)	1.1454 (2)	0.0187 (5)
C6	0.0065 (5)	0.9211 (4)	1.0125 (2)	0.0208 (5)
C1'	0.0657 (5)	0.9306 (3)	0.8067 (2)	0.0198 (5)
C2'	0.3013 (5)	0.9414 (4)	0.7758 (2)	0.0205 (5)
C5'	0.0051 (5)	0.5322 (4)	0.6246 (2)	0.0229 (6)
C4'	0.0512 (5)	0.7293 (4)	0.6625 (2)	0.0208 (5)
C3'	0.3020 (5)	0.7879 (3)	0.6914 (2)	0.0189 (5)
O8	0.3314 (4)	0.6415 (3)	1.41947 (17)	0.0277 (5)
H4'	−0.031 (6)	0.802 (5)	0.603 (2)	0.021 (8)*
H5B'	0.062 (6)	0.505 (5)	0.554 (2)	0.025 (8)*
H3'	0.396 (6)	0.692 (4)	0.729 (2)	0.013 (7)*
H03'	0.359 (8)	0.783 (7)	0.540 (3)	0.050 (12)*
H2'	0.346 (6)	1.048 (6)	0.747 (3)	0.030 (9)*
H6	−0.156 (6)	0.943 (4)	1.002 (2)	0.016 (7)*
H05'	0.252 (8)	0.401 (7)	0.723 (3)	0.049 (11)*
H5A'	−0.164 (7)	0.515 (5)	0.606 (3)	0.031 (9)*
H01	0.062 (7)	0.903 (6)	1.173 (3)	0.036 (10)*
H1'	−0.029 (6)	1.029 (5)	0.774 (3)	0.026 (9)*
H08B	0.333 (8)	0.707 (7)	1.364 (4)	0.045 (12)*
H08A	0.436 (12)	0.565 (11)	1.421 (4)	0.09 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O4	0.0174 (9)	0.0357 (11)	0.0210 (8)	−0.0051 (9)	0.0058 (7)	−0.0036 (9)
O4'	0.0213 (10)	0.0189 (9)	0.0242 (10)	−0.0045 (7)	0.0072 (8)	−0.0027 (7)
O2	0.0222 (10)	0.0220 (10)	0.0233 (9)	0.0008 (8)	0.0072 (8)	0.0003 (7)
N1	0.0164 (10)	0.0189 (10)	0.0239 (10)	−0.0010 (9)	0.0062 (8)	−0.0026 (9)
C4	0.0170 (12)	0.0152 (11)	0.0234 (11)	−0.0018 (10)	0.0066 (9)	−0.0026 (10)
O5'	0.0224 (10)	0.0160 (8)	0.0286 (9)	−0.0029 (8)	0.0089 (8)	0.0003 (7)
O3'	0.0390 (13)	0.0229 (10)	0.0256 (10)	−0.0133 (9)	0.0143 (9)	−0.0039 (8)
N3	0.0161 (11)	0.0255 (12)	0.0238 (10)	0.0008 (9)	0.0055 (8)	−0.0027 (9)
C5	0.0178 (12)	0.0134 (11)	0.0236 (11)	0.0013 (10)	0.0045 (9)	−0.0013 (9)
C2	0.0182 (12)	0.0127 (11)	0.0264 (12)	−0.0006 (10)	0.0075 (10)	−0.0018 (10)
C6	0.0172 (12)	0.0170 (11)	0.0285 (13)	0.0016 (10)	0.0055 (10)	−0.0042 (10)
C1'	0.0204 (13)	0.0130 (11)	0.0251 (12)	0.0008 (10)	0.0018 (10)	−0.0012 (10)
C2'	0.0220 (14)	0.0174 (12)	0.0221 (12)	−0.0043 (10)	0.0044 (10)	0.0015 (10)
C5'	0.0263 (16)	0.0222 (13)	0.0201 (13)	−0.0074 (11)	0.0041 (11)	−0.0016 (10)
C4'	0.0220 (14)	0.0203 (12)	0.0195 (12)	−0.0015 (10)	0.0023 (10)	0.0007 (10)
C3'	0.0224 (14)	0.0148 (11)	0.0195 (12)	−0.0043 (10)	0.0039 (10)	0.0008 (9)
O8	0.0368 (13)	0.0220 (10)	0.0269 (11)	0.0082 (9)	0.0128 (10)	0.0011 (8)

Geometric parameters (Å, º)

O4—C4	1.343 (3)	O5'—C5'	1.432 (3)
O4—C2'	1.471 (3)	O3'—C3'	1.416 (3)
O4'—C4'	1.434 (3)	N3—C2	1.371 (3)
O4'—C1'	1.438 (3)	C5—C6	1.360 (4)
O2—C2	1.242 (3)	C5—C1'	1.494 (4)
N1—C6	1.350 (4)	C1'—C2'	1.543 (4)
N1—C2	1.379 (3)	C2'—C3'	1.522 (4)
C4—N3	1.313 (3)	C5'—C4'	1.506 (4)
C4—C5	1.409 (4)	C4'—C3'	1.542 (4)
C4—O4—C2'	108.67 (19)	O4'—C1'—C5	110.5 (2)
C4'—O4'—C1'	105.6 (2)	O4'—C1'—C2'	105.8 (2)
C6—N1—C2	124.0 (2)	C5—C1'—C2'	101.8 (2)
N3—C4—O4	120.0 (2)	O4—C2'—C3'	111.5 (2)
N3—C4—C5	127.4 (2)	O4—C2'—C1'	106.9 (2)
O4—C4—C5	112.6 (2)	C3'—C2'—C1'	105.1 (2)
C4—N3—C2	115.6 (2)	O5'—C5'—C4'	113.2 (2)
C6—C5—C4	115.7 (2)	O4'—C4'—C5'	109.2 (2)
C6—C5—C1'	135.1 (3)	O4'—C4'—C3'	104.5 (2)
C4—C5—C1'	109.1 (2)	C5'—C4'—C3'	116.3 (2)
O2—C2—N3	121.6 (2)	O3'—C3'—C2'	110.9 (2)
O2—C2—N1	119.3 (2)	O3'—C3'—C4'	112.9 (2)
N3—C2—N1	119.1 (2)	C2'—C3'—C4'	102.9 (2)
N1—C6—C5	118.2 (3)
C2'—O4—C4—N3	−177.1 (2)	C4—C5—C1'—C2'	−8.2 (2)
C2'—O4—C4—C5	2.7 (3)	C4—O4—C2'—C3'	−122.2 (2)
O4—C4—N3—C2	179.7 (2)	C4—O4—C2'—C1'	−7.9 (3)
C5—C4—N3—C2	−0.1 (4)	O4'—C1'—C2'—O4	−106.0 (2)
N3—C4—C5—C6	0.6 (4)	C5—C1'—C2'—O4	9.5 (2)
O4—C4—C5—C6	−179.2 (2)	O4'—C1'—C2'—C3'	12.6 (3)
N3—C4—C5—C1'	−176.3 (3)	C5—C1'—C2'—C3'	128.1 (2)
O4—C4—C5—C1'	3.9 (3)	C1'—O4'—C4'—C5'	166.7 (2)
C4—N3—C2—O2	−179.9 (2)	C1'—O4'—C4'—C3'	41.6 (2)
C4—N3—C2—N1	−0.4 (3)	O5'—C5'—C4'—O4'	−54.6 (3)
C6—N1—C2—O2	179.9 (2)	O5'—C5'—C4'—C3'	63.3 (3)
C6—N1—C2—N3	0.3 (4)	O4—C2'—C3'—O3'	−112.0 (2)
C2—N1—C6—C5	0.2 (4)	C1'—C2'—C3'—O3'	132.6 (2)
C4—C5—C6—N1	−0.6 (3)	O4—C2'—C3'—C4'	127.0 (2)
C1'—C5—C6—N1	175.3 (3)	C1'—C2'—C3'—C4'	11.6 (3)
C4'—O4'—C1'—C5	−143.3 (2)	O4'—C4'—C3'—O3'	−151.8 (2)
C4'—O4'—C1'—C2'	−33.8 (3)	C5'—C4'—C3'—O3'	87.7 (3)
C6—C5—C1'—O4'	−72.2 (4)	O4'—C4'—C3'—C2'	−32.2 (2)
C4—C5—C1'—O4'	103.9 (2)	C5'—C4'—C3'—C2'	−152.7 (2)
C6—C5—C1'—C2'	175.7 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3′—H03′···O8^i	0.88 (4)	1.79 (4)	2.663 (3)	175 (5)
O5′—H05′···O2^ii	0.93 (5)	1.82 (5)	2.735 (3)	169 (5)
N1—H01···O5′^iii	0.84 (4)	1.91 (4)	2.744 (3)	175 (4)
O8—H08B···O2	0.83 (5)	2.06 (5)	2.862 (3)	162 (5)
O8—H08A···O3′^ii	0.84 (8)	1.91 (8)	2.728 (3)	165 (7)
C2′—H2′···O2^iv	0.91 (4)	2.56 (4)	3.406 (4)	155 (3)
C3′—H3′···O2^ii	0.95 (3)	2.59 (3)	3.479 (3)	155 (2)
C6—H6···O4^v	0.97 (4)	2.48 (3)	3.337 (4)	146 (2)
C6—H6···N3^v	0.97 (4)	2.51 (4)	3.379 (4)	148 (2)

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