1-Methyl-3,5-diphenyl-1H-1,2,4-di­aza­phosphole

In the title N-substituted 1,2,4-di­aza­phosphole, C₁₅H₁₃N₂P, the phenyl rings make dihedral angles of 29.8 (3) and 55.9 (3)° with the 1,2,4-di­aza­phosphole ring. In the crystal, no significant inter­molecular inter­actions are present.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.058
• wR factor = 0.122
• Data-to-parameter ratio = 18.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      9.670 Check
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      2.211 Check

Alert level G
PLAT199_ALERT_1_G Reported _cell_measurement_temperature ..... (K)        293 Check
PLAT200_ALERT_1_G Reported   _diffrn_ambient_temperature ..... (K)        293 Check
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Th(Min) ...          3 Report
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600        412 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 ALERT level G = General information/check it is not something unexpected

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Structural commentary

Five-membered 1,2,4-di­aza­phospho­les are a unique type of aromatic heterocyclic compound with lone pairs of electrons on the hetero-atoms, π-electrons on the heterocyclic ring and a low-valent phospho­rus (σ²λ³) atom. Recently, the investigation of 1,2,4-di­aza­phospho­lide complexes as well as symmetric and asymmetric 1,2,4-di­aza­phospho­les have attracted considerable inter­est (Zheng et al., 2006; Wan et al., 2008; Liu et al., 2014; Wang et al., 2014). We have synthesized the N-substituted analogue, 1-methyl-3,5-di­phenyl-1,2,4-di­aza­phosphole, C₁₅H₁₃N₂P, using a modified procedure of Schmidpeter & Willhalm (1984) and its crystal structure is reported herein.

In the structure of the title compound (Fig. 1), the dihedral angles between the planes of the two substitutent benzene rings defined by the atoms C4—C6···C25 and C2–C10···C32 and the di­aza­phosphole ring are 29.8 (3) and 55.9 (3)°, respectively. The C22–P4–C24 angle in the ring is 86.59 (11)°, comparable to those found in the other 1,2,4-di­aza­phospho­les (Liu et al., 2014; Wang et al., 2014). In the crystal, no significant inter­molecular inter­actions are present.

S2. Synthesis and crystallization

All manipulations were carried out in an inert atmosphere of N₂ using standard Schlenk techniques in a N₂ filled glovebox. Solvents were dried over and distilled from Na/K alloy prior to use. The procedure used in the synthesis of the title compound follows that for the synthesis of other similar 1,2,4-di­aza­phospho­les (Schmidpeter & Willhalm, 1984), by the reaction of 1,3-di­phenyl-1,3-bis­(di­methyl­amino)-2-phospho­ryl chloride and pre-dried methyl hydrazine. The product from the reaction was extracted with ether (2 x 10 ml) and after evaporation of the solvent over several days, gave pale yellow crystals of the title compound [m.p. 381 K (dec.)].

¹H NMR (600 MHz, 298 K, CDCl₃): 7.95 (d, 2 H, Ar–H), 7.50 (s, 5 H, Ar–H), 7.28 (m, 3 H, Ar–H), 4.06 (s, 3 H, N–CH₃) p.p.m.. ³¹P{¹H} NMR (600 MHz, 298 K, CDCl₃): 89.22(s) p.p.m.. Anal. calcd for C₁₅H₁₃N₂P: C 71.43; H 5.16; N 11.11%. Found: C 71.41; H, 5.14; N, 11.09%.

S3. Refinement

All H atoms were placed in calculated positions (C—H = 0.93 Å (aromatic) or 0.96 Å (methyl) and were refined using a riding model with U_iso(H) = 1.2U_eq(C) (aromatic) or 1.5U_eq(C) (methyl).

Related literature

For background on 1,2,4-diazaphospholes, see: Zheng et al. (2006); Wan et al. (2008); Wang et al. (2014); Liu et al. (2014). For the synthesis of a similar compound, see: Schmidpeter & Willhalm (1984).

S4. Experimental

All manipulations were carried out in an inert atmosphere of N₂ using standard Schlenk techniques in a N₂ filled glovebox. Solvents were dried over and distilled from Na/K alloy prior to use. The procedure used in the synthesis of the title compound follows that for the synthesis of other similar 1,2,4-diazaphospholes (Schmidpeter & Willhalm, 1984), by the reaction of 1,3-diphenyl-1,3-bis(dimethylamino)-2-phosphoryl chloride and pre-dried methyl hydrazine. The product from the reaction was extracted with ether (2 × 10 ml) and after evaporation of the solvent over several days, gave pale-yellow crystals of the title compound [m.p. 381 K (dec.)].

¹H NMR (600 MHz, 298 K, CDCl₃): 7.95 (d, 2 H, Ar–H), 7.50 (s, 5 H, Ar–H), 7.28 (m, 3 H, Ar–H), 4.06 (s, 3 H, N–CH₃) p.p.m. ³¹P{¹H} NMR (600 MHz, 298 K, CDCl₃): 89.22(s) p.p.m. Analysis calculated for C₁₅H₁₃N₂P: C 71.43; H 5.16; N 11.11%. Found: C 71.41; H, 5.14; N, 11.09%.

S5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

Structure description

Five-membered 1,2,4-diazaphospholes are a unique type of aromatic heterocyclic compound with lone pairs of electrons on the hetero-atoms, π-electrons on the heterocyclic ring and a low-valent phosphorus (σ²λ³) atom. Recently, the investigation of 1,2,4-diazaphospholide complexes as well as symmetric and asymmetric 1,2,4-diazaphospholes have attracted considerable interest (Zheng et al., 2006; Wan et al., 2008; Liu et al., 2014; Wang et al., 2014). We have synthesized the N-substituted analogue, 1-methyl-3,5-diphenyl-1,2,4-diazaphosphole, C₁₅H₁₃N₂P, using a modified procedure of Schmidpeter & Willhalm (1984) and its crystal structure is reported herein.

In the structure of the title compound (Fig. 1), the dihedral angles between the planes of the C2- and C4 phenyl rings are 29.8 (3) and 55.9 (3)°, respectively. The C22—P4—C24 angle in the ring is 86.59 (11)°, comparable to those found in the other 1,2,4-diazaphospholes (Liu et al., 2014; Wang et al., 2014). In the crystal, no significant intermolecular interactions are present.

Computing details

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures

Fig. 1. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are omitted.

1-Methyl-3,5-diphenyl-1H-1,2,4-diazaphosphole

Crystal data

C15H13N2P	Dx = 1.262 Mg m^−3
Mr = 252.24	Melting point < 381 K
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.2774 (7) Å	Cell parameters from 1740 reflections
b = 7.4256 (5) Å	θ = 3.0–28.8°
c = 17.4094 (11) Å	µ = 0.19 mm^−1
β = 92.472 (6)°	T = 293 K
V = 1327.38 (15) Å^3	Block, pale yellow
Z = 4	0.15 × 0.12 × 0.10 mm
F(000) = 528

Data collection

Agilent SuperNova CCD diffractometer	3046 independent reflections
Radiation source: fine-focus sealed tube	1740 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ω scans	θmax = 28.8°, θmin = 3.0°
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012)	h = −13→8
Tmin = 0.910, Tmax = 0.938	k = −9→9
5468 measured reflections	l = −22→21

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.058	H-atom parameters constrained
wR(F^2) = 0.122	w = 1/[σ^2(Fo^2) + (0.040P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max = 0.001
3046 reflections	Δρmax = 0.23 e Å^−3
164 parameters	Δρmin = −0.24 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.

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

	x	y	z	Uiso*/Ueq
P4	0.31686 (7)	0.04887 (9)	0.44478 (4)	0.0519 (2)
N1	0.15290 (19)	−0.1345 (2)	0.51899 (11)	0.0437 (5)
N3	0.18769 (19)	−0.0033 (2)	0.56999 (11)	0.0456 (5)
C10	0.1779 (2)	−0.2671 (3)	0.39049 (13)	0.0410 (6)
C22	0.2097 (2)	−0.1300 (3)	0.45053 (13)	0.0420 (6)
C24	0.2733 (2)	0.1051 (3)	0.53853 (13)	0.0400 (6)
C25	0.3189 (2)	0.2621 (3)	0.58452 (14)	0.0417 (6)
C28	0.2761 (2)	−0.3685 (3)	0.35986 (13)	0.0474 (6)
H28	0.3621	−0.3510	0.3771	0.057*
C32	0.0228 (3)	−0.4223 (3)	0.30712 (14)	0.0522 (7)
H32	−0.0628	−0.4401	0.2893	0.063*
C2	0.0506 (3)	−0.2939 (3)	0.36285 (14)	0.0493 (7)
H2	−0.0164	−0.2251	0.3820	0.059*
C4	0.3262 (3)	0.2565 (3)	0.66411 (15)	0.0564 (7)
H4	0.3051	0.1507	0.6893	0.068*
C6	0.3644 (3)	0.4059 (4)	0.70655 (16)	0.0684 (8)
H6	0.3690	0.4000	0.7600	0.082*
C9	0.3524 (3)	0.4214 (3)	0.54900 (15)	0.0539 (7)
H9	0.3497	0.4278	0.4956	0.065*
C13	0.0629 (3)	−0.2704 (3)	0.54697 (15)	0.0599 (8)
H13A	0.0790	−0.2876	0.6012	0.090*
H13B	0.0758	−0.3821	0.5206	0.090*
H13C	−0.0252	−0.2304	0.5374	0.090*
C16	0.2470 (3)	−0.4960 (3)	0.30355 (16)	0.0598 (8)
H16	0.3135	−0.5632	0.2831	0.072*
C17	0.3956 (3)	0.5628 (4)	0.6702 (2)	0.0698 (9)
H17	0.4206	0.6636	0.6990	0.084*
C19	0.1204 (3)	−0.5234 (3)	0.27784 (15)	0.0576 (7)
H19	0.1011	−0.6104	0.2407	0.069*
C31	0.3900 (3)	0.5713 (4)	0.59168 (19)	0.0674 (8)
H31	0.4114	0.6776	0.5670	0.081*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
P4	0.0577 (5)	0.0558 (5)	0.0429 (4)	−0.0135 (4)	0.0110 (3)	−0.0050 (3)
N1	0.0443 (13)	0.0410 (12)	0.0462 (12)	−0.0041 (10)	0.0076 (10)	0.0010 (10)
N3	0.0493 (14)	0.0443 (12)	0.0434 (13)	−0.0012 (10)	0.0057 (10)	−0.0037 (9)
C10	0.0455 (16)	0.0400 (14)	0.0377 (13)	0.0005 (12)	0.0038 (11)	0.0014 (10)
C22	0.0446 (16)	0.0422 (14)	0.0394 (14)	0.0016 (12)	0.0047 (11)	−0.0024 (11)
C24	0.0398 (15)	0.0395 (13)	0.0407 (13)	−0.0002 (11)	0.0027 (11)	0.0016 (11)
C25	0.0378 (15)	0.0439 (15)	0.0434 (14)	0.0022 (12)	0.0006 (11)	−0.0024 (12)
C28	0.0465 (17)	0.0527 (16)	0.0432 (14)	0.0024 (13)	0.0027 (12)	−0.0036 (12)
C32	0.0521 (18)	0.0525 (17)	0.0514 (16)	−0.0041 (14)	−0.0040 (13)	−0.0028 (13)
C2	0.0419 (17)	0.0507 (16)	0.0557 (16)	0.0043 (13)	0.0049 (12)	−0.0072 (13)
C4	0.062 (2)	0.0616 (18)	0.0450 (16)	−0.0014 (14)	−0.0018 (13)	−0.0023 (13)
C6	0.063 (2)	0.089 (2)	0.0525 (17)	0.0070 (18)	−0.0053 (15)	−0.0200 (18)
C9	0.0567 (18)	0.0507 (16)	0.0540 (16)	−0.0032 (14)	−0.0017 (13)	−0.0006 (14)
C13	0.067 (2)	0.0576 (17)	0.0569 (17)	−0.0163 (15)	0.0161 (14)	0.0028 (13)
C16	0.061 (2)	0.0613 (18)	0.0582 (18)	0.0120 (15)	0.0090 (14)	−0.0128 (13)
C17	0.0509 (19)	0.071 (2)	0.087 (2)	0.0057 (16)	−0.0084 (17)	−0.0338 (19)
C19	0.072 (2)	0.0525 (16)	0.0485 (16)	−0.0003 (16)	0.0015 (15)	−0.0105 (12)
C31	0.065 (2)	0.0474 (17)	0.089 (2)	−0.0029 (14)	−0.0044 (18)	−0.0060 (16)

Geometric parameters (Å, º)

P4—C22	1.731 (2)	C17—C31	1.367 (5)
P4—C24	1.761 (2)	C19—C32	1.369 (4)
N1—N3	1.356 (2)	C24—C25	1.479 (3)
N1—C13	1.466 (3)	C2—H2	0.9300
N1—C22	1.350 (3)	C4—H4	0.9300
N3—C24	1.328 (3)	C6—H6	0.9300
C2—C10	1.389 (4)	C9—H9	0.9300
C2—C32	1.381 (3)	C13—H13A	0.9600
C4—C6	1.381 (4)	C13—H13B	0.9600
C4—C25	1.385 (4)	C13—H13C	0.9600
C6—C17	1.371 (4)	C16—H16	0.9300
C9—C25	1.385 (3)	C17—H17	0.9300
C9—C31	1.384 (4)	C19—H19	0.9300
C10—C22	1.485 (3)	C28—H28	0.9300
C10—C28	1.384 (3)	C31—H31	0.9300
C16—C19	1.373 (4)	C32—H32	0.9300
C16—C28	1.386 (3)
C22—P4—C24	86.59 (11)	C10—C2—H2	120.00
N3—N1—C13	115.43 (18)	C32—C2—H2	120.00
N3—N1—C22	116.65 (17)	C6—C4—H4	120.00
C13—N1—C22	127.83 (18)	C25—C4—H4	120.00
N1—N3—C24	109.04 (18)	C4—C6—H6	120.00
C10—C2—C32	120.4 (3)	C17—C6—H6	120.00
C6—C4—C25	120.9 (2)	C25—C9—H9	120.00
C4—C6—C17	120.2 (3)	C31—C9—H9	119.00
C25—C9—C31	121.1 (3)	N1—C13—H13A	110.00
C2—C10—C22	121.2 (2)	N1—C13—H13B	109.00
C2—C10—C28	118.7 (2)	N1—C13—H13C	109.00
C22—C10—C28	120.13 (19)	H13A—C13—H13B	110.00
C19—C16—C28	120.3 (2)	H13A—C13—H13C	109.00
C6—C17—C31	120.0 (3)	H13B—C13—H13C	109.00
C16—C19—C32	119.8 (2)	C19—C16—H16	120.00
P4—C22—N1	111.74 (16)	C28—C16—H16	120.00
P4—C22—C10	127.33 (17)	C6—C17—H17	120.00
N1—C22—C10	120.93 (19)	C31—C17—H17	120.00
P4—C24—N3	115.97 (16)	C16—C19—H19	120.00
P4—C24—C25	126.96 (17)	C32—C19—H19	120.00
N3—C24—C25	117.0 (2)	C10—C28—H28	120.00
C4—C25—C9	117.9 (2)	C16—C28—H28	120.00
C4—C25—C24	121.3 (2)	C9—C31—H31	120.00
C9—C25—C24	120.7 (2)	C17—C31—H31	120.00
C10—C28—C16	120.4 (2)	C2—C32—H32	120.00
C9—C31—C17	119.9 (3)	C19—C32—H32	120.00
C2—C32—C19	120.5 (3)
C24—P4—C22—N1	−0.38 (17)	C4—C6—C17—C31	−0.5 (5)
C24—P4—C22—C10	179.4 (2)	C31—C9—C25—C4	−1.0 (4)
C22—P4—C24—N3	0.70 (18)	C31—C9—C25—C24	177.3 (2)
C22—P4—C24—C25	−177.4 (2)	C25—C9—C31—C17	0.6 (5)
C13—N1—N3—C24	177.24 (19)	C2—C10—C22—P4	−122.8 (2)
C22—N1—N3—C24	0.5 (3)	C2—C10—C22—N1	57.0 (3)
N3—N1—C22—P4	0.0 (2)	C28—C10—C22—P4	55.9 (3)
N3—N1—C22—C10	−179.74 (18)	C28—C10—C22—N1	−124.4 (2)
C13—N1—C22—P4	−176.26 (19)	C2—C10—C28—C16	−1.0 (3)
C13—N1—C22—C10	4.0 (3)	C22—C10—C28—C16	−179.7 (2)
N1—N3—C24—P4	−0.8 (2)	C28—C16—C19—C32	1.0 (4)
N1—N3—C24—C25	177.49 (18)	C19—C16—C28—C10	−0.3 (4)
C32—C2—C10—C22	−179.9 (2)	C6—C17—C31—C9	0.2 (5)
C32—C2—C10—C28	1.5 (3)	C16—C19—C32—C2	−0.6 (4)
C10—C2—C32—C19	−0.7 (4)	P4—C24—C25—C4	−152.0 (2)
C25—C4—C6—C17	0.1 (5)	P4—C24—C25—C9	29.8 (3)
C6—C4—C25—C9	0.7 (4)	N3—C24—C25—C4	30.0 (3)
C6—C4—C25—C24	−177.6 (2)	N3—C24—C25—C9	−148.3 (2)