cis-Bis(3,6-di­hydro-2H-1,2-oxazine-N)­di­iodo­platinum(II) and cis-bis(3,4,5,6-tetra­hydro-2H-1,2-oxazine-N)­di­iodo­platinum(II)

The title complexes, [Pt(C₄H₇NO)₂I₂], (I), and [Pt(C₄H₉NO)₂I₂], (II), possess similar square-planar coordination geometries with modest distortions from ideality. For (I), the cis-L-Pt-L angles are in the range 87.0 (4)-94.2 (3)°, while the trans angles are 174.4 (3) and 176.4 (3)°. For (II), cis-L-Pt-L are 86.1 (8)-94.2 (6)° and trans-L-Pt-L are 174.4 (6) and 177.4 (5)°. One 3,6-di­hydro-2H-1,2-oxazine ligand in (I) is rotated so that the N-O bond is out of the square plane by approximately 70°, while the N-C bond is only ca 20° out of the plane. The other oxazine ligand is rotated so that the N-C bond is about 80° out of the plane, while the N-O bond is out of the plane by approximately 24°. In (II), the 3,4,5,6-tetra­hydro-2H-1,2-oxazine ligands are also positioned with one having the N-O bond further out of the plane and the other having the N-C bond positioned in that fashion. Both ligands, however, are rotated approximately 90° compared with their positions in (I). In both complexes, this results in an unsymmetrical distortion of the I-Pt-N bond angles in which one is expanded and the other contracted. These features are compared to those of reported cis-di­amine­di­iodo­platinum(II) complexes.

S1. Comment

As part of a continuing study of potential chemotherapeutic alternatives to cisplatin and carboplatin (Lippard, 1982; Rosenberg, 1985), we have been examining the use of 1,2-oxazines as the cis-amine ligands in these platinum complexes (Dyksterhouse et al., 2000). Compounds (I) and (II) were obtained as intermediate products in an as yet unsuccessful effort to prepare cis-bis(1,2-oxazine)-1,1-cyclobutanedicarboxylatoplatinum(II). They are part of a small family of cis-diaminediiodoplatinum(II) complexes that have been structurally characterized. The Pt coordination geometry (Table 1) shows modest distortions from the square-planar ideal. All cis angles are within 4° of 90°, while the trans angles differ by 6 and 4° from 180°. The mean deviation from the PtI₂N₂ least-squares plane is 0.028 (5) Å, though only N2 is displaced by more than two s.u.'s, −0.17 (1) Å. The Pt—I and Pt—N distances are consistent with those seen in similar complexes (Raudaschl-Sieber et al., 1986; Oksanen et al., 1989; Zimmerman et al., 1999). The 3,6-dihydro-2H-1,2-oxazine ligands in (I) are bulkier than those found in the reported complexes, leading to an irregular distortion in the ligand bond angles not seen in the others. In cis-diamminediiodoplatinum(II) (N,N-dimethylacetamide solvate) (Raudaschl-Sieber et al., 1986), the I—Pt—I angle is approximately 93°, while the I—Pt—N and N—Pt—N angles are all about 89°, which is attributed to the large size of the I atoms. An essentially identical pattern is found in cis-diiodobis(2-hydroxyethylamine)platinum(II) (Zimmerman et al., 1999). In cis-bis(cyclopropylamine)diiodoplatinum(II) (Oksanen et al., 1989), the I—Pt—I angle is about 94°, the I—Pt—N angles are 86 and 88°, and the N—Pt—N angle is nearly 93°. The opening of the N—Pt—N angle and closing of the I—Pt—N angles occurs presumably to avoid non-bonded contacts between the cyclopropyl groups. In (I), the expansion and contraction of the bond angles is lopsided: N2—Pt—I1 is 87.6 (3)°, while N1—Pt—I2 is 94.0 (3)°, and N1—Pt—N2 is actually smaller [87.2 (4)°] than in any of the other cis-amine complexes. This distortion is consistent with the rotations of the oxazine groups with respect to the ligand plane. The N2 ring is twisted so that C8 is nearly perpendicular to the plane [torsion angle I1—Pt—N2—C8 − 83.1 (8)°], thus minimizing contacts with I1, allowing for a smaller bond angle. To avoid unfavorable contacts with the N2 ring, the N1 ring is rotated so that O1 is out of the plane [torsion angle I2—Pt—N1—O1 107.9 (6)°] and C4 is directed away from the other ring. This conformation, however, places C4 in closer contact with I2 [torsion angle I2—Pt—N1—C4 − 20.8 (9)°] which apparently results in the larger I—Pt—N angle. Both oxazine rings are in cyclohexene-like conformations with normal bond distances and angles. The absolute configurations at N are opposite for the two rings. The coordination environment for (II) (Table 2) is similar to that in (I). The average deviation from the PtI₂N₂ least-squares plane is 0.030 (8) Å with both N atoms displaced above the plane by significant amounts [0.089 (19) Å for N1 and 0.058 (17) Å for N2]. As in (I), the trans bond angles differ from 180° by roughly 6 and 4°. Also, the cis bond angles show the same type of unsymmetrical distortion in which one I—Pt—N angle is opened and the other is contracted. In this case, the N1 ring is rotated so that the N1—C4 bond is approximately perpendicular to the ligand plane [torsion angle I2—Pt—N1—C4 78 (2)°] allowing for closer contact with the neighboring I atom. Since O1 is then directed towards the N2 ring, the latter twists away so that O2 is out of the plane and C8 is directed towards I1 [torsion angles I1—Pt—N2—O2 − 108 (1)°; I1—Pt—N2—C8 17 (2)°], resulting in a larger N2—Pt—I1 angle. Both oxazine ligands possess a chair conformation with bond distances and angles similar to those in reported saturated oxazine derivatives (Riddell et al., 1974; Holzapfel et al., 1987). As is the case for the 3,6-dihydro-2H-1,2-oxazine ligands in (I), the 3,4,5,6-tetrahydro-2H-1,2-oxazine ligands in (II) have opposite absolute configurations at N.

S2. Experimental

Preparation of (I): to a solution of potassium tetrachloroplatinate (2.09 g, 5.04 mmol) in water (50 ml) were added a solution of potassium iodide (8.34 g, 50.2 mmol) in water (5 ml), followed by 3,6-dihydro-2H-1,2-oxazine (0.876 g, (10.3 mmol). The mixture was stirred for 45 min and the yellow powder that formed was isolated by filtration (yield 3.12 g). Recrystallization from a mixture of dimethylformamide and water yielded small orange crystals of (I). Preparation of (II): to a solution of potassium tetrachloroplatinate (1.66 g, 4.00 mmol) in water (35 ml) were added a solution of potassium iodide (6.64 g, 40.0 mmol) in water (5 ml), followed by a solution of 3,4,5,6-tetrahydro-2H-1,2-oxazine hydrochloride (0.988 g, 8.00 mmol) and potassium hydroxide (0.5 g, 9 mmol) in water (15 ml). The resulting mixture was stirred for 50 min and the orange powder that formed (2.17 g) was filtered. Crystals of (II) were obtained by recrystallization from a dimethylformamide/water solution.

Computing details

For both compounds, data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1991). Program(s) used to solve structure: MITHRIL (Gilmore, 1983) for (I); SIR (Burla et al., 1989) for (II). For both compounds, program(s) used to refine structure: TEXSAN; software used to prepare material for publication: TEXSAN.

(I)

Crystal data

[Pt(C4H7NO)2I2]	F(000) = 1104
Mr = 619.11	Dx = 2.996 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.7107 Å
a = 10.146 (4) Å	Cell parameters from 23 reflections
b = 9.003 (7) Å	θ = 9.2–13.4°
c = 15.035 (2) Å	µ = 14.8 mm^−1
β = 92.28 (2)°	T = 296 K
V = 1372 (1) Å^3	Flat needle, yellow–orange
Z = 4	0.30 × 0.20 × 0.20 mm

Data collection

Rigaku AFC-6S diffractometer	1544 reflections with I > 3σ(I)
Radiation source: X-ray tube	Rint = 0.022
Graphite monochromator	θmax = 25.0°
ω scans	h = 0→12
Absorption correction: ψ scan (North et al., 1968)	k = 0→11
Tmin = 0.039, Tmax = 0.052	l = −18→18
2718 measured reflections	3 standard reflections every 150 reflections
2387 independent reflections	intensity decay: 3.5%

Refinement

Refinement on F	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.030	H-atom parameters not refined
wR(F^2) = 0.028	Weighting scheme based on measured s.u.'s w = 4Fo^2/σ^2(Fo^2)
S = 1.48	(Δ/σ)max = 0.016
1544 reflections	Δρmax = 1.49 e Å^−3
136 parameters	Δρmin = −0.70 e Å^−3

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

	x	y	z	Uiso*/Ueq
Pt	0.42222 (5)	0.17948 (6)	0.94926 (3)	0.0380 (1)
I1	0.46637 (10)	0.21387 (10)	1.11910 (6)	0.0532 (3)
I2	0.17500 (9)	0.1301 (1)	0.97163 (6)	0.0592 (3)
O1	0.4186 (9)	0.2999 (10)	0.7707 (6)	0.056 (3)
O2	0.6654 (8)	0.170 (1)	0.8513 (5)	0.048 (3)
N1	0.4065 (10)	0.152 (1)	0.8104 (6)	0.045 (3)
N2	0.6197 (10)	0.233 (1)	0.9333 (7)	0.048 (4)
C1	0.471 (1)	0.278 (2)	0.6834 (10)	0.068 (6)
C2	0.406 (2)	0.161 (2)	0.6303 (9)	0.068 (6)
C3	0.324 (1)	0.071 (2)	0.6646 (9)	0.060 (5)
C4	0.299 (1)	0.073 (2)	0.7613 (9)	0.053 (5)
C5	0.810 (1)	0.183 (2)	0.8465 (9)	0.057 (5)
C6	0.854 (1)	0.337 (2)	0.8684 (9)	0.056 (5)
C7	0.782 (1)	0.432 (2)	0.9066 (10)	0.059 (5)
C8	0.644 (1)	0.398 (2)	0.9318 (9)	0.052 (5)
H1	0.4715	0.0886	0.8094	0.0543
H2	0.6823	0.1803	0.9586	0.0570
H3	0.4665	0.3717	0.6504	0.0736
H4	0.5656	0.2559	0.6901	0.0736
H5	0.4263	0.1525	0.5679	0.0773
H6	0.2782	−0.0009	0.6265	0.0714
H7	0.2149	0.1217	0.7713	0.0609
H8	0.2891	−0.0280	0.7837	0.0609
H9	0.8358	0.1566	0.7896	0.0664
H10	0.8508	0.1168	0.8899	0.0664
H11	0.9425	0.3688	0.8515	0.0652
H12	0.8196	0.5296	0.9223	0.0708
H13	0.5807	0.4443	0.8894	0.0597
H14	0.6245	0.4417	0.9894	0.0597

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pt	0.0370 (3)	0.0423 (3)	0.0351 (3)	0.0021 (3)	0.0072 (2)	0.0029 (3)
I1	0.0678 (7)	0.0555 (6)	0.0366 (5)	0.0046 (5)	0.0060 (5)	−0.0004 (4)
I2	0.0405 (6)	0.0836 (8)	0.0543 (6)	−0.0038 (5)	0.0140 (5)	−0.0018 (6)
O1	0.071 (7)	0.051 (6)	0.046 (6)	0.006 (5)	0.007 (5)	0.016 (5)
O2	0.041 (5)	0.058 (6)	0.044 (5)	0.002 (5)	0.011 (4)	−0.004 (5)
N1	0.050 (7)	0.055 (8)	0.031 (6)	0.012 (6)	0.007 (5)	0.007 (5)
N2	0.031 (6)	0.069 (9)	0.046 (7)	0.008 (6)	0.002 (5)	−0.001 (6)
C1	0.06 (1)	0.09 (1)	0.050 (9)	0.022 (10)	0.030 (8)	0.037 (9)
C2	0.06 (1)	0.10 (1)	0.042 (9)	0.00 (1)	0.000 (8)	−0.002 (10)
C3	0.048 (9)	0.09 (1)	0.040 (9)	0.008 (9)	−0.014 (7)	−0.004 (9)
C4	0.036 (8)	0.06 (1)	0.059 (10)	−0.001 (8)	−0.002 (7)	−0.005 (8)
C5	0.034 (8)	0.08 (1)	0.060 (9)	0.004 (9)	0.017 (7)	0.027 (9)
C6	0.053 (9)	0.07 (1)	0.045 (9)	−0.020 (9)	−0.002 (7)	0.003 (8)
C7	0.054 (10)	0.06 (1)	0.06 (1)	−0.017 (9)	0.009 (8)	−0.002 (9)
C8	0.07 (1)	0.041 (9)	0.048 (9)	−0.007 (8)	−0.003 (8)	−0.010 (7)

Geometric parameters (Å, º)

Pt—I1	2.593 (1)	C7—C8	1.50 (2)
Pt—I2	2.582 (1)	N1—H1	0.87
Pt—N1	2.103 (9)	N2—H2	0.87
Pt—N2	2.085 (10)	C1—H3	0.98
O1—N1	1.47 (1)	C1—H4	0.98
O1—C1	1.45 (1)	C2—H5	0.97
O2—N2	1.45 (1)	C3—H6	0.97
O2—C5	1.47 (1)	C4—H7	0.97
N1—C4	1.47 (1)	C4—H8	0.98
N2—C8	1.50 (2)	C5—H9	0.93
C1—C2	1.46 (2)	C5—H10	0.96
C2—C3	1.28 (2)	C6—H11	0.98
C3—C4	1.49 (2)	C7—H12	0.98
C5—C6	1.49 (2)	C8—H13	0.98
C6—C7	1.28 (2)	C8—H14	0.98
I1—Pt—I2	91.31 (4)	O1—C1—H3	109
I1—Pt—N1	174.4 (3)	O1—C1—H4	109
I1—Pt—N2	87.5 (3)	C2—C1—H3	109
I2—Pt—N1	94.2 (3)	C2—C1—H4	109
I2—Pt—N2	176.4 (3)	H3—C1—H4	104
N1—Pt—N2	87.0 (4)	C3—C2—H5	120
N1—O1—C1	106.4 (9)	C1—C2—H5	118
N2—O2—C5	111.2 (9)	C4—C3—H6	119
Pt—N1—O1	106.9 (7)	C2—C3—H6	119
Pt—N1—C4	125.4 (8)	N1—C4—H7	110
O1—N1—C4	107.7 (9)	N1—C4—H8	111
Pt—N2—O2	110.3 (7)	C3—C4—H7	110
Pt—N2—C8	112.8 (8)	C3—C4—H8	110
O2—N2—C8	108.6 (9)	H7—C4—H8	105
N1—C4—C3	110 (1)	O2—C5—H9	110
C1—C2—C3	121 (1)	O2—C5—H10	109
C2—C3—C4	121 (1)	C6—C5—H9	110
O1—C1—C2	114 (1)	C6—C5—H10	108
N2—C8—C7	110 (1)	H9—C5—H10	110
C5—C6—C7	123 (1)	C7—C6—H11	118
C6—C7—C8	122 (1)	C5—C6—H11	119
O2—C5—C6	110 (1)	C8—C7—H12	119
Pt—N1—H1	94	C6—C7—H12	119
O1—N1—H1	121	N2—C8—H13	109
C4—N1—H1	103	N2—C8—H14	110
Pt—N2—H2	121	C7—C8—H13	110
O2—N2—H2	84	C7—C8—H14	111
C8—N2—H2	116	H13—C8—H14	105

(II)

Crystal data

[Pt(C4H9NO)2I2]	Z = 2
Mr = 623.14	F(000) = 560
Triclinic, P1	Dx = 2.841 Mg m^−3
a = 9.379 (5) Å	Mo Kα radiation, λ = 0.7107 Å
b = 9.537 (4) Å	Cell parameters from 21 reflections
c = 8.950 (4) Å	θ = 11.8–16.1°
α = 91.10 (4)°	µ = 13.9 mm^−1
β = 98.37 (4)°	T = 296 K
γ = 66.98 (4)°	Slab, orange
V = 728.3 (7) Å^3	0.30 × 0.15 × 0.15 mm

Data collection

Rigaku AFC-6S diffractometer	1673 reflections with I > 3σ(I)
Radiation source: X-ray tube	Rint = 0.079
Graphite monochromator	θmax = 25.0°
ω–2θ scans	h = 0→11
Absorption correction: ψ scan (North et al., 1968)	k = −11→11
Tmin = 0.076, Tmax = 0.124	l = −11→11
2734 measured reflections	3 standard reflections every 150 reflections
2561 independent reflections	intensity decay: 7.0%

Refinement

Refinement on F	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.052	H-atom parameters not refined
wR(F^2) = 0.058	Weighting scheme based on measured s.u.'s w = 4Fo^2/σ^2(Fo^2)
S = 2.70	(Δ/σ)max = 0.004
1673 reflections	Δρmax = 2.35 e Å^−3
136 parameters	Δρmin = −3.17 e Å^−3

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

	x	y	z	Uiso*/Ueq
Pt	0.7141 (1)	0.4680 (1)	0.5236 (1)	0.0330 (3)
I1	0.8218 (2)	0.2057 (2)	0.6657 (2)	0.0520 (6)
I2	0.6089 (2)	0.6056 (2)	0.7630 (2)	0.0490 (6)
O1	0.608 (2)	0.668 (2)	0.253 (2)	0.043 (5)
O2	0.924 (2)	0.420 (2)	0.310 (2)	0.048 (6)
N1	0.638 (2)	0.677 (2)	0.416 (2)	0.040 (6)
N2	0.795 (2)	0.380 (2)	0.328 (2)	0.036 (7)
C1	0.538 (3)	0.816 (4)	0.179 (3)	0.058 (10)
C2	0.649 (4)	0.898 (3)	0.203 (3)	0.07 (1)
C3	0.691 (3)	0.912 (3)	0.376 (3)	0.06 (1)
C4	0.742 (4)	0.757 (3)	0.459 (3)	0.07 (1)
C5	0.947 (3)	0.414 (4)	0.153 (3)	0.06 (1)
C6	0.999 (3)	0.249 (4)	0.099 (3)	0.07 (1)
C7	0.875 (3)	0.194 (3)	0.128 (3)	0.056 (10)
C8	0.844 (3)	0.218 (3)	0.288 (3)	0.052 (9)
H1	0.5487	0.7351	0.4439	0.0460
H2	0.7197	0.4300	0.2541	0.0439
H3	0.5087	0.8083	0.0731	0.0684
H4	0.4450	0.8775	0.2199	0.0684
H5	0.7467	0.8372	0.1621	0.0745
H6	0.6077	0.9951	0.1493	0.0745
H7	0.7705	0.9544	0.3978	0.0656
H8	0.5987	0.9841	0.4139	0.0656
H9	0.7565	0.7681	0.5662	0.0747
H10	0.8466	0.6929	0.4343	0.0747
H11	0.8486	0.4771	0.0897	0.0644
H12	1.0212	0.4571	0.1391	0.0644
H13	1.0130	0.2454	−0.0061	0.0731
H14	1.0996	0.1875	0.1560	0.0731
H15	0.7800	0.2494	0.0589	0.0639
H16	0.9071	0.0879	0.1046	0.0639
H17	0.9370	0.1594	0.3573	0.0582
H18	0.7636	0.1828	0.3065	0.0582

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pt	0.0274 (6)	0.0320 (6)	0.0353 (6)	−0.0089 (5)	−0.0013 (4)	0.0023 (4)
I1	0.055 (1)	0.044 (1)	0.047 (1)	−0.009 (1)	0.0029 (10)	0.0109 (9)
I2	0.040 (1)	0.060 (1)	0.044 (1)	−0.017 (1)	0.0033 (9)	−0.0102 (10)
O1	0.04 (1)	0.04 (1)	0.05 (1)	−0.017 (9)	−0.008 (9)	0.012 (9)
O2	0.05 (1)	0.05 (1)	0.04 (1)	−0.012 (10)	−0.005 (9)	0.005 (9)
N1	0.02 (1)	0.04 (1)	0.05 (1)	−0.01 (1)	−0.009 (10)	0.01 (1)
N2	0.02 (1)	0.06 (2)	0.04 (1)	−0.03 (1)	0.004 (9)	−0.01 (1)
C1	0.04 (2)	0.07 (2)	0.05 (2)	−0.01 (2)	0.00 (1)	0.01 (2)
C2	0.06 (2)	0.04 (2)	0.08 (2)	0.00 (2)	0.02 (2)	0.04 (2)
C3	0.06 (2)	0.06 (2)	0.05 (2)	−0.02 (2)	0.01 (2)	−0.01 (2)
C4	0.10 (3)	0.02 (2)	0.06 (2)	−0.03 (2)	−0.03 (2)	0.01 (1)
C5	0.04 (2)	0.09 (3)	0.05 (2)	−0.04 (2)	−0.01 (1)	0.02 (2)
C6	0.04 (2)	0.09 (3)	0.04 (2)	0.00 (2)	0.01 (1)	−0.01 (2)
C7	0.05 (2)	0.05 (2)	0.06 (2)	−0.01 (2)	0.02 (2)	−0.02 (2)
C8	0.05 (2)	0.03 (2)	0.07 (2)	−0.01 (1)	0.01 (2)	0.00 (1)

Geometric parameters (Å, º)

Pt—I1	2.583 (3)	N2—H2	0.88
Pt—I2	2.604 (2)	C1—H3	0.96
Pt—N1	2.05 (2)	C1—H4	0.96
Pt—N2	2.05 (2)	C2—H5	0.99
O1—N1	1.45 (2)	C2—H6	0.96
O1—C1	1.43 (3)	C3—H7	0.97
O2—N2	1.43 (2)	C3—H8	0.97
O2—C5	1.44 (3)	C4—H9	0.96
N1—C4	1.47 (3)	C4—H10	0.98
N2—C8	1.48 (3)	C5—H11	0.98
C1—C2	1.52 (4)	C5—H12	0.96
C2—C3	1.56 (4)	C6—H13	0.97
C3—C4	1.53 (4)	C6—H14	0.96
C5—C6	1.55 (4)	C7—H15	0.97
C6—C7	1.50 (4)	C7—H16	0.97
C7—C8	1.50 (3)	C8—H17	0.96
N1—H1	0.87	C8—H18	0.98
I1—Pt—I2	91.11 (8)	C1—C2—H6	113
I1—Pt—N1	177.4 (5)	C3—C2—H5	109
I1—Pt—N2	94.2 (6)	C3—C2—H6	112
I2—Pt—N1	88.5 (6)	H5—C2—H6	105
I2—Pt—N2	174.4 (6)	C2—C3—H7	112
N1—Pt—N2	86.1 (8)	C2—C3—H8	109
N1—O1—C1	111 (1)	C4—C3—H7	111
N2—O2—C5	110 (1)	C4—C3—H8	109
Pt—N1—O1	111 (1)	H7—C3—H8	106
Pt—N1—C4	113 (1)	N1—C4—H9	111
O1—N1—C4	111 (1)	N1—C4—H10	108
Pt—N2—O2	108 (1)	C3—C4—H9	110
Pt—N2—C8	125 (1)	C3—C4—H10	107
O2—N2—C8	105 (1)	H9—C4—H10	106
O1—C1—C2	111 (2)	O2—C5—H11	110
C1—C2—C3	108 (2)	O2—C5—H12	111
C2—C3—C4	109 (2)	C6—C5—H11	108
N1—C4—C3	114 (2)	C6—C5—H12	111
O2—C5—C6	111 (2)	H11—C5—H12	106
C5—C6—C7	106 (2)	C5—C6—H13	111
C6—C7—C8	110 (2)	C5—C6—H14	109
N2—C8—C7	112 (2)	C7—C6—H13	113
Pt—N1—H1	108	C7—C6—H14	111
O1—N1—H1	107	H13—C6—H14	107
C4—N1—H1	105	C6—C7—H15	109
Pt—N2—H2	106	C6—C7—H16	109
O2—N2—H2	106	C8—C7—H15	110
C8—N2—H2	105	C8—C7—H16	111
O1—C1—H3	111	H15—C7—H16	107
O1—C1—H4	110	N2—C8—H17	108
C2—C1—H3	110	N2—C8—H18	109
C2—C1—H4	108	C7—C8—H17	111
H3—C1—H4	108	C7—C8—H18	111
C1—C2—H5	110	H17—C8—H18	106