The first substitution reactions of N,N-spiro bridged octachlorobiscyclotriphosphazene

Polyhedron 98 (2015) 230–237

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The first substitution reactions of N,N-spiro bridged octachlorobiscyclotriphosphazene Serap Besßli ⇑, Semih Dog˘an, Ceylan Mutlu, Fatma Yuksel Department of Chemistry, Gebze Technical University, Gebze, Kocaeli, Turkey

a r t i c l e

i n f o

Article history: Received 24 March 2015 Accepted 31 May 2015 Available online 12 June 2015 Keywords: Cyclotriphosphazene Crystal structure Spiro Bridged 1,2-Ethanediol

a b s t r a c t The reaction of the N,N-spiro bridged octachlorobiscyclotriphosphazene {N3P3Cl4[br-N(CH2)5CH3]2N3P3Cl4} (1), in three (1:1 stoichiometries, 1:2 and 1:3.5), with the sodium derivative of 1,2-ethanediol in THF solution at room temperature produced five products, the mono-spiro derivative {N3P3Cl2[O(CH2)2O] [br-N(CH2)5CH3]2N3P3Cl4} (2), cis and trans di-spiro derivatives {N3P3Cl2[O(CH2)2O][br-N(CH2)5CH3]2 [O(CH2)2O]N3P3Cl2} (3, 5), the ipsilateral di-spiro isomer {N3P3[O(CH2)2O]2[br-N(CH2)5CH3]2N3P3Cl4} (4) and the tetra-spiro derivative {N3P3[O(CH2)2O]2[br-N(CH2)5CH3]2[O(CH2)2O]2N3P3}, (6), whose structures have been characterized by elemental analysis, mass spectrometry, 1H and 31P NMR spectroscopy and X-ray crystallography. The nucleophilic substitution reactions of the N,N-spiro bridged octachlorobiscyclotriphosphazene were investigated for the first time and X-ray crystallographic studies of all the structures (2–6) have been reported as the first examples of derivatives of this new class of ring system in the literature. Ó 2015 Elsevier Ltd. All rights reserved.

1. Introduction Cyclophosphazenes, which consist of a P–N backbone, are an important member of inorganic ring systems due to their very active P-halogen bonds [1–7]. Hexachlorocyclotriphosphazene (N3P3Cl6) is the most popular compound in the cyclophosphazene series, so it is commonly used as a precursor to prepare of other cyclophosphazene derivatives [8–17]. Recently, new types of heterocyclic structures having a phosphorus-nitrogen skeleton were synthesised from the deprotonation reaction of aminocyclotriphosphazene derivatives containing P–NHR groups in the side chains [18,19]. One of these types is the N,N-spiro bridged octachlorobiscyclotriphosphazene derivatives, which form fused cyclophosphazene–cyclophosphazane– cyclophosphazene rings and have eight active PCl bonds suitable for forming new molecular structures. The investigation of nucleophilic substitution reactions of these new cyclophosphazene structures is a new area for phosphorus–nitrogen chemistry. In the present work, the nucleophilic substitution reaction of the N,N-spiro bridged octachlorobiscyclotriphosphazene derivative 1 with disodium salts of 1,2-ethanediol has been investigated for different molar ratios of the reactants in THF at room temperature

⇑ Corresponding author at: Department of Chemistry, Gebze Technical University, Gebze, Kocaeli 41400, Turkey. Tel.: +90 262 6053013; fax: +90 262 6053005. E-mail address: [email protected] (S. Besßli). http://dx.doi.org/10.1016/j.poly.2015.05.047 0277-5387/Ó 2015 Elsevier Ltd. All rights reserved.

in order to understand the reaction susceptibility of compound 1, determine of the product variety and compare the 31P NMR spectra of the products with known conventional results. It is known that di-functional reagents lead to different types of products, such as open chain, bridge, spiro, ansa, oligomer and polymer or their mixtures [20–31]. Hence 1,2-ethanediol, which is a short chain aliphatic diol, was selected so that spiro products are favorable. The results may be summarized as follows: (i) the reactions lead to five new products: a mono-spiro derivative (2), di-spiro derivatives (3– 5) and a tetra-spiro derivative (6); (ii) all the possible di-spiro isomers were obtained and their crystal structures were determined; (iii) new types of 31P NMR spectra, which will be useful for determining the structures of similar new compounds, were recorded.

2. Experimental 2.1. Materials and methods Hexachlorocyclotriphosphazene (Aldrich) was purified by fractional crystallization from n-hexane. 1,2-Ethanediol (Merck) was dried over a 4 Å molecular sieve. Hexylamine (Merck) was used as received. Tetrahydrofuran (THF) (Aldrich) was distilled over a sodium/potassium alloy under an atmosphere of dry argon. Sodium hydride, 60% dispersion in mineral oil (Merck), was used, but prior to use the oil was removed by washing with dry hexane (Merck) followed by decantation. All reactions were performed

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under a dry argon atmosphere. CDCl3 for NMR spectroscopy was obtained from Merck. Analytical Thin Layer Chromatography (TLC) was performed on Merck silica gel plates (Merck, Kieselgel 60, 0.25 mm thickness) with F254 indicator. Column chromatography was performed on silica gel (Merck, Kieselgel 60, 70–230 mesh; for 3 g. crude mixture, 100 g. silica gel was used). Elemental analyses were obtained using an Elementar Vario MICRO Cube. Mass analyses were recorded on a Bruker MALDI– TOF (Matrix-Assisted Laser Desorption/Ionization-Time-Of-Flight) spectrometer using 2,5-dihydroxybenzoic acid as a matrix. 1H and 31P NMR spectra were recorded for all compounds in CDCl3 on a Varian INOVA 500 MHz spectrometer using TMS as an internal reference for 1H and 85% H3PO4 as an external reference for 31P NMR measurements. 2.2. X-ray crystallography Intensity data were recorded on a Bruker APEX II QUAZAR diffractometer using mono-chromatized Mo Ka radiation (k = 0.71073 Å). Absorption corrections were performed by the multi-scan method implemented in SADABS [32] and space groups were determined using XPREP implemented in APEX2 [33]. The structures were determined using the direct methods procedure in SHELXS-97

and refined by full-matrix least squares on F2 using

SHELXL-97 [34]. All non-hydrogen atoms were refined with anisotropic displacement factors and C–H hydrogen atoms were placed in calculated positions and allowed to ride on the parent atom. The final geometrical calculations were carried out with PLATON [35] and MERCURY [36] programs and the molecular drawings were done with the DIAMOND [37] program.

2.3. Synthesis Compound 1 was prepared as in the literature [18]. 2.3.1. Synthesis of compound 2 N,N-Spiro bridged biscyclotriphosphazene {N3P3Cl4[brN(CH2)5CH3]2N3P3Cl4} (1) (0.38 g; 0.5 mmol) and 1,2 ethanediol (0.02 g; 0.35 mmol) were dissolved in 15 mL of dry THF under an argon atmosphere in a 50 mL three-necked round-bottomed flask. NaH (60% oil suspension, 0.03 g; 0.7 mmol) in 5 mL of dry THF was quickly added to the stirred solution under an argon atmosphere. The reaction mixture was then stirred for 24 h at room temperature and the reaction was followed on TLC silica gel plates using n-hexane-THF (2:1) as the eluent. One new product was observed. The reaction mixture was filtered to remove sodium chloride and any other insoluble materials. The solvent was removed under reduced pressure and the resulting colorless oil was subjected to column chromatography, using n-hexane-THF (2:1) as the mobile phase. Unreacted starting compound (1) (0.14 g, 37%) was eluted first from the column. The second product was the mono-spiro derivative, {N3P3Cl2[O(CH2)2O][br-N(CH2)5CH3]2N3P3Cl4} (2). Compound 2 was crystallized from n-hexane-dichloromethane (3:1) and obtained as a white crystal. Yield: 0.12 g, 32%; Mp: 132 °C Anal. Calc. for 2, C14H30Cl6N8O2P6 (M = 741.0): C, 22.69; H, 4.08; N, 15.12. Found: C, 22.65; H, 4.03; N, 14.99%; [M+H]+: 741.9. 1H NMR, CDCl3, 298 K, d (ppm): 0.89 (t, 6H, –CH3), 1.27, 1.87 (m, 16H, –CH2–), 3.08 (m, 4H, –NCH2–), 4.46 (m, 4H, – OCH2–). 31P NMR decoupled, CDCl3, 298 K, d (ppm): 0.85 {[P(NN)spiro] belong to A0 2X0 , 2JPP = 48.1, 45.0 Hz (the bridge-head P atoms of different cyclophosphazene rings)}; 6.60 {[P(NN)-spiro] belong to ABX, 2JPP = 45.0 Hz (the bridge-head P atoms of different cyclophosphazene rings)}; 25.66 (2 PCl2, 2JPP = 48.1 Hz); 31.09 (PCl2); 31.13 [P(OO)-spiro].

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2.3.2. Synthesis of compounds 3–5 N,N-Spiro bridged biscyclotriphosphazene {N3P3Cl4[brN(CH2)5CH3]2N3P3Cl4} (1) (0.75 g; 1.0 mmol) and 1,2-ethanediol (0.12 g; 2.0 mmol) were dissolved in 15 mL of dry THF in a 50 mL three-necked round-bottomed flask. NaH (60% oil suspension, 0.03 g, 0.70 mmol) in 10 mL of dry THF was quickly added to the stirred solution under an argon atmosphere. The reaction was stirred for a further 24 h at room temperature and followed by TLC on silica gel plates using n-hexane-THF (1:1) as the mobile phase. Three new products were observed. The reaction mixture was filtered to remove the sodium chloride and any other insoluble material. The solvent was removed under reduced pressure and the crude product was subjected to column chromatography using n-hexane-THF (1:1) as the mobile phase. Compound 2 (0.05 g, 7%) was eluted first from the column. The second product was the trans di-spiro derivative {N3P3Cl2[O(CH2)2O][br-N(CH2)5CH3]2[O(CH2)2O]N3P3Cl2} (3), the third product was the ipsilateral di-spiro derivative {N3P3[O(CH2)2O]2[br-N(CH2)5CH3]2N3P3Cl4} (4) and the last product was cis di-spiro {N3P3Cl2[O(CH2)2O][brN(CH2)5CH3]2[O(CH2)2O]N3P3Cl2} (5). The colorless solids obtained were crystallized from n-hexane-dichloromethane (3:1) to give white crystals. 3: Yield: 0.17 g, 23%; Mp: 293 °C. Anal. Calc. for 3, C16H34Cl4N8O4P6 (M = 730.2): C, 26.32; H, 4.69; N, 15.35. Found: C, 26.07; H, 4.69; N, 15.37%; [M]+: 730. 1H NMR, CDCl3, 298 K, d (ppm): 0.94 (t, 6H, –CH3), 1.35, 1.65 (m, 16H, –CH2–), 3.10 (m, 4H, –NCH2–), 4.49 (m, 8H, –OCH2–). 31P NMR decoupled, CDCl3, 298 K, d (ppm): 6.71 {2 [P(NN)-spiro]}; 31.04 {[P(OO)-spiro] and (PCl2)}. 4: Yield: 0.18 g, 24%; Mp: 195 °C. Anal. Calc. for 4, C16H34Cl4N8O4P6 (M = 730.2): C, 26.32; H, 4.69; N, 15.35. Found: C, 26.10; H, 4.68; N, 15.30%; [M+H]+: 731.0. 1H NMR, CDCl3, 298 K, d (ppm): 0.90 (t, 6H, –CH3), 1.30, 1.76 (m, 16H, –CH2–), 3.06 (m, 4H, –NCH2–), 4.43 (m, 8H, –OCH2–). 31P NMR decoupled, CDCl3, 298 K, d (ppm): 1.34 {[P(NN)-spiro], 2JPP = 47.4 Hz}; 2 11.78{[P(NN)-spiro] JPP = 71.7 Hz}; 25.27 [(2xPCl2), 2 JPP = 47.4 Hz]; 37.80 {[P(OO)-spiro], 2JPP = 71.7 Hz}. 5: Yield: 0.04 g, 6%; Mp: 177 °C. Anal. Calc. for 5, C16H34Cl4N8O4P6 (M = 730.2): C, 26.32; H, 4.69; N, 15.35. Found: C, 26.15; H, 4.68; N, 15.33%; [M+H]+: 731.0 1H NMR, CDCl3, 298 K, d (ppm): 0.80 (t, 6H, –CH3), 1.22, 1.66 (m, 16H, –CH2–), 2.96 (m, 4H, –NCH2–), 4.35 (m, 8H, –OCH2–). 31P NMR decoupled, CDCl3, 298 K, d (ppm): 6.76 {2x [P(NN)-spiro]}; 31.13 {[P(OO)spiro] and (PCl2)}. 2.3.3. Synthesis of compound 6 N,N-Spiro bridged biscyclotriphosphazene {N3P3Cl4[brN(CH2)5CH3]2N3P3Cl4} (1) (0.38 g; 0.5 mmol) and 1,2-ethanediol (0.11 g; 1.75 mmol) were dissolved in 15 mL of dry THF in a 50 mL three-necked round-bottomed flask. The reaction mixture was cooled in an ice-bath and NaH (60% oil suspension, 0.14 g; 3.5 mmol) in 5 mL of dry THF was quickly added to the stirred solution under an argon atmosphere. The reaction was stirred for a further 24 h at room temperature, followed by TLC on silica gel plates using n-hexane-THF (2:3) as the mobile phase. One product was observed. The reaction mixture was filtered to remove the sodium chloride and any other insoluble material. The solvent was removed under reduced pressure and the crude product was subjected to column chromatography using n-hexane-THF (2:3) as the mobile phase. Compound 6 was crystallized from cyclohexane-dichloromethane (3:1) to give thin stick white crystals. The product is the tetra-spiro derivative {N3P3[O(CH2)2O]2[brN(CH2)5CH3]2[O(CH2)2O]2N3P3} (6). 6: Yield: 0.05 g, 15%; Mp 254 °C. Anal. Calc. for 6, C20H42N8O8P6 (M = 708.5): C, 33.91; H, 5.98; N, 15.82. Found: C, 33.76; H, 5.92; N,

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15.80%; [M+2H]+: 710.2. 1H NMR, CDCl3, 298 K, d (ppm): 0.90 (t, 6H, –CH3), 1.27, 1.45 (m, 16H, –CH2–), 3.77 (m, 4H, –NCH2–), 4.39 (m, 16H, –OCH2–). 31P NMR decoupled, CDCl3, 298 K, d (ppm): 12.03 [P(NN)-spiro]; 37.59 [P(OO)-spiro].

31

P NMR spectroscopy is essential for characterization of phosphazene compounds. The interesting 31P NMR spectra were recorded for these original cyclophosphazene compounds. The mass and elemental analysis results of compound 2 indicated that two of the chlorine atoms in compound 1 had been replaced with one 1,2-ethanedioxy group. Although five different phosphorus nuclei are expected for mono-spiro compound, the proton decoupled 31P NMR spectrum of compound 2 displayed four different peak groups (Fig. 1a). It was shown that the [P(OO)spiro] group and one of the [PCl2] groups have very close chemical shift values by evaluation of the integration ratios and the proton coupled 31P NMR spectrum (Fig. 1b). Compound 2 has ABX and A0 2X0 spin systems for the two cyclotriphosphazene rings which make up the structure. Subsequently, X-ray analysis of compound 2 confirmed that it has the mono spiro structure. The mass and elemental analysis results of compounds 3, 4 and 5 indicated that four of the chlorine atoms in compound 1 had been replaced with two 1,2-ethanedioxy groups and it was likely that these compounds were di-spiro isomers. Whereas the proton decoupled 31P NMR spectrum of compound 4 exhibited A2X and A0 2X0 spin systems (Fig. 2a), compounds 3 and 5 each have one AA0 BB0 XX0 spin system with very close chemical shifts values (Fig. 3). A2X and A0 2X0 spin systems are compatible with the

3. Results and discussion 3.1. Characterization of the reaction products by 31P NMR spectroscopy The novel cyclophosphazene compound N,N-spiro bridged octachlorobiscyclotriphosphazene (1) provides a new cyclophosphazene with eight P–Cl bonds available for nucleophilic substitution reactions. Therefore, compound 1 has been reacted with the disodium salt of 1,2-ethanediol at different mole ratios in THF. The reactions lead to five new products: the mono-spiro derivative (2), three isomers of di-spiro derivatives (3–5) and the tetra-spiro derivative (6) (Scheme 1). All the products were characterized by elemental analysis, mass spectrometry, 1H and 31P NMR spectroscopies and X-ray crystallography. The results of mass and elemental analysis, 1H and 31P NMR spectroscopy for each new compound are provided as part of the analytical data in the synthesis section.

Cl P Cl

N

Cl

N

P

P

N Cl

N P

Cl

N

N

N

P

N

P

N

P

N

N P

Cl

Cl

Cl

Cl

Cl

Cl

Cl

N

P

N

P

P

N

Cl

Cl

Cl

P

(1) Cl

(1) O O

Cl

P

N

P

N

P

N Cl

Cl

N

P

N

P

P

N Cl

Cl

Cl mono-spiro (2)

O O

Cl

P

N P

N P Cl

N

N

P N

P

P

O

N

N

N

Cl

Cl

O

Cl P

O

O

N P

P

P

N

N

P

Cl

Cl

O

trans-di-spiro (3)

O

O

P

N

N O

P

N

P

N

P

P

O

P

O N O

O tetra-spiro (6)

Scheme 1. Structures of the obtained compounds.

P

P

N

O N

N

P Cl

Cl cis-di-spiro (5)

O N

N P

Cl

ipsilateral-di-spiro (4)

P

N

N

N Cl

O

P

O

P

O

O

Cl

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Fig. 1. (a) Proton decoupled

31

31

Fig. 2. (a) Proton decoupled

31

31

P NMR spectrum of compound 2. (b) Proton coupled

P NMR spectrum of compound 4. (b) Proton coupled

ipsilateral di-spiro isomer (4), having four different phosphorus nuclei. The proton coupled 31P NMR spectrum also consistent with the probable structure, as shown in Fig. 2b. In this instance, compounds 3 and 5 should be the trans and cis di-spiro isomers. Although there are three different environments for both compounds, two signals groups were observed in the proton decoupled 31 P NMR spectra. Evaluation of the integral ratios and the proton coupled 31P NMR spectra indicated that the [P(OO)spiro] and [PCl2] groups have very close chemical shifts values, as seen for

P NMR spectrum of compound 2.

P NMR spectrum of compound 4.

the mono-spiro compound. X-ray crystallography confirmed that compound 3 is the trans di-spiro isomer, compound 4 is the ipsilateral di-spiro isomer and compound 5 is the cis di-spiro isomer. The proton decoupled 31P NMR spectrum of compound 6 has an 0 AA X2X02 spin system, similar to the spectrum of the starting compound 1 [18]; the chemical shifts of the [P(NN)-spiro] groups in the compound were 12.03 ppm and the chemical shifts of the [P(OO)spiro] groups were 37.59 ppm. The spectrum also exhibited an additional two-bond coupling constant resulting from coupling

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Fig. 3. (a) Proton decoupled 31P NMR spectrum of compound 3. (b) Proton decoupled 31P NMR spectrum of compound 5. (c) Proton coupled 31P NMR spectrum of compound 3.

paths between the bridge-head P atoms of the [P(NN)-spiro] groups of different cyclophosphazene rings. 3.2. Characterization of the compounds by X-ray crystallography The crystal structures of compounds 2–6 are presented in Figs. 4–8 and the data collection and refinement parameters are reported in Table 1. Selected bond and conformational parameters of compounds 2–6 are presented in Table 2. The starting compound consists of a fused three ring structure in which two cyclotriphosphazene rings, which are essentially

Fig. 5. A view of the molecular structure for 3 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and the hydrogen atoms have been omitted for clarity. The structure of compound 3 has a center of symmetry.

Fig. 4. A view of the molecular structure for 2 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and the hydrogen atoms have been omitted for clarity.

planar and on the same plane, are linked by the four-membered cyclophosphazane ring [18]. The products (2–6) retain the unique main structure of the starting compound; hence they contain two cyclotriphosphazene rings which are bridged by a perpendicular P2N2 ring. The 5-membered spiro ring (P/O/C/C/O) has the envelope or twisted envelop conformation, and both carbon atoms are out of the plane in all the structures (Table 2). The new compounds are achiral due to a plane of symmetry and also a center of symmetry in compounds 3 and 6. Although the bond lengths and bond angles of the cyclotriphosphazene rings,

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Fig. 6. A view of the molecular structure for 4 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. The hydrogen atoms have been omitted, and only one orientation of the disordered hexylamine chains, which are substituted on the N4 and N5 atoms of compound 4, has been presented for clarity.

Fig. 7. A view of the molecular structures for 5 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and the hydrogen atoms have been omitted for clarity.

(PN)3, of all compounds (2–6) are found within the normal range for many cyclotriphosphazenes [38–40], there are small differences in the P–N bond lengths and N–P–N bond angles because of the substitution by the 1,2-ethanedioxy moiety. The molecular structure of 2 confirmed that it is the mono-spiro compound (Fig. 4). Its unsubstituted cyclotriphosphazene ring is nearly planar, as observed in the starting compound (1), with the maximum deviation from the mean plane being only 0.0528 Å (for atom N8). However, the 1,2-ethanedioxy-substituted cyclotriphosphazene ring has a flattened chair conformation and the maximum deviation from the mean plane is 0.0868 Å (for atom N3). Compounds 3 and 5 are symmetrically di-spiro-substituted structures. In both compounds, each of the cyclotriphosphazenes ring includes one spiro-1,2-ethanedioxy group, but while the two spiro rings are in trans positions in compound 3 (Fig. 5), they are

235

Fig. 8. A view of the molecular structures for 6 with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. The hydrogen atoms and cyclohexane solvent molecule have been omitted for clarity. The structure of compound 6 has a center of symmetry.

in cis positions in compound 5 (Fig. 7). Having a symmetry center in compound 3, the cyclotriphosphazene ring is in the flattened boat conformation and the maximum deviation from the mean plane is 0.1004 Å (for atom P1). In compound 5, one of the cyclotriphosphazene ring is in a twisted conformation and the maximum deviation from the mean plane is 0.1155 Å (for atom P2), while other one is nearly planar and the maximum deviation from the mean plane is 0.0403(17) Å (for atom N6). Compound 4 is also a di-spiro-substituted system with two 1,2ethanedioxy moieties, but the two substituted groups are linked to the same cyclotriphosphazene ring, as shown Fig. 6. The unsubstituted cyclotriphosphazene ring of compound 4 is in the flattened boat conformation, [max. deviation is 0.0815 Å (for atom P4)], while the disubstituted one is in a slightly twisted conformation [max. deviation is 0.0860 Å (for atom N1)]. The X-ray analysis of compound 6 showed that four 1,2-ethanedioxy groups are substituted on two cyclophosphazene rings and the molecule has center and plane of symmetry (Fig. 8). The cyclophosphazene ring is in the flattened chair conformation and the maximum deviation from the mean plane is 0.0783 Å (for atom N2). Considering the analyses of all the compounds above, it is proven that substitution of compound 1 caused a deviation of the cyclotriphosphazene rings from planarity. The puckering amplitude values of the substituted compounds increases to two or three times compared to the starting compound, as shown Table 2. An investigation of the crystal structures of compounds 2–6 showed that there are many short intermolecular contacts where the separation between the donor and acceptor atoms is less than 3.5 Å. 3.3. The reactivity of compound 1 and the distribution of the di-spiro isomers The priority of this work was to understand the reactivity of compound 1, which is new type cyclophosphazene compound, and to compare its reactivity with the parent hexachlorocyclotriphosphazene (trimer). It was seen that compound 1 is stable and the eight PCl bonds are active, similar to the P–Cl bonds in the conventional cyclophosphazenes, hence it may be used in the

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Table 1 X-ray crystallographic data and refinement parameters for compounds 2–6. Compound

2

3

4

5

6

Empirical formula Formula weight Temperature (K) Crystal system Space group a (Å) b (Å) c (Å) a (°) b (°) c (°) Volume (Å3) Z Dcalc (Mg m3) Absorption coefficient (mm1) F(0 0 0) Crystal size (mm) hmax (°) Reflections collected Independent reflections Rint (merging R value) Parameter R (F2 > 2rF2) wR (all data) Goodness-of-fit on F2 Dq maximum/minimum (e Å3)

C14H30Cl6N8O2P6 740.98 120(2) triclinic  P1

C16H34Cl4N8O4P6 730.13 120(2) triclinic  P1

C16H34Cl4N8O4P6 730.13 120(2) triclinic  P1

8.7406(3) 13.8723(4) 14.3054(4) 64.4080(16) 83.1940(17) 87.1240(17) 1553.36(8) 2 1.584 0.892 756 0.11  0.18  0.35 27.53 20 309 7133 0.0452 327 0.0337 0.0866 1.028 0.510/0.465

8.2010(7) 8.3820(7) 12.9304(11) 89.176(5) 73.229(5) 63.830(4) 757.18(11) 1 1.601 0.748 376 0.11  0.23  0.23 25.02 8775 2674 0.0343 173 0.0289 0.0727 1.061 0.382/0.368

8.593(6) 13.208(8) 14.767(9) 76.471(11) 75.400(17) 82.312(11) 1571.9(18) 2 1.543 0.721 752 0.14  0.21  0.31 27.55 28 016 7222 0.0264 367 0.0335 0.0897 1.041 0.883/0.482

C16H34Cl4N8O4P6 730.13 120(2) monoclinic P121/c1 10.6404(4) 17.5007(7) 17.5799(7) 90 101.7530(8) 90 3205.0(2) 4 1.513 0.707 1504 0.24  0.26  0.42 28.33 29 841 7991 0.0388 345 0.0330 0.0887 1.031 0.544/0.355

C20H42N8O8P6 708.45 120(2) monoclinic P121/n1 13.8574(13) 8.6209(8) 16.3548(15) 90 105.493(6) 90 1882.8(3) 2 1.398 0.341 840 0.02  0.05  0.25 28.40 50 938 4732 0.1011 218 0.0477 0.1332 1.021 0.414/0.388

Table 2 Some bond and conformational parameters of compounds 1–6. 1 [18]*

2

3*

4

5

6*

P1–N1 P1–N3 P2–N1 P2–N2 P3–N2 P3–N3 P1–N4 P1–N5 P4–N4 P4–N5 P4–N6 P4–N8 P5–N6 P5–N7 P6–N7 P6–N8 N1–P1–N3 N1–P2–N2 N2–P3–N3 P2–N1–P1 P3–N2–P2 P3–N3–P1 P4–N6–P5 P5–N7–P6 P4–N8–P6 N6–P4–N8 N6–P5–N7 N7–P6–N8 Puckering amplitude, Q for P3N3 rings

1.5954(15) 1.5976(15) 1.5723(15) 1.5814(16) 1.5823(16) 1.5721(15) 1.6719(14)

1.5821(19) 1.6042(17) 1.5842(18) 1.5919(17) 1.5688(19) 1.5805(17) 1.6808(19)

0.0379(15) (N1)

1.5903(18) 1.5810(18) 1.5875(18) 1.5846(18) 1.5757(18) 1.5892(18) 1.699(2) 1.6740(19) 1.6601(19) 1.658(2) 1.5994(18) 1.6014(18) 1.5659(18) 1.5843(18) 1.5854(18) 1.5732(18) 117.10(9) 116.29(9) 116.83(9) 121.90(10) 123.52(11) 122.56(10) 122.92(10) 119.47(11) 122.85(10) 114.61(10) 119.64(9) 119.23(9) 0.1238(13) 0.1175(13) 0.0860(18) (N1) 0.0815(7) (P4) 0.219(2) (C2) 0.179(2) (C4)

1.5829(15) 1.5987(17) 1.5827(15) 1.5924(17) 1.5681(17) 1.5798(16) 1.6710(15) 1.6668(16) 1.6754(16) 1.6665(15) 1.5855(16) 1.5973(15) 1.5830(16) 1.5840(17) 1.5672(17) 1.5762(15) 115.64(8) 115.71(8) 119.71(9) 124.19(10) 120.95(10) 121.18(10) 124.85(10) 121.47(10) 121.20(10) 115.60(8) 116.22(8) 120.27(8) 0.1778(13) Planar 0.1155(7) (P2) 0.0403(17) (N6) 0.169(2) (C1) 0.132(4) (C3)

1.584(2) 1.589(2) 1.581(2) 1.578(2) 1.575(2) 1.578(2) 1.671(2)

Max. deviation for P3N3 rings

1.5843(16) 1.5947(17) 1.5843(18) 1.5926(18) 1.5700(17) 1.5773(17) 1.6821(17) 1.6802(18) 1.6714(18) 1.6585(17) 1.5965(18) 1.5949(16) 1.5730(18) 1.5790(18) 1.5831(18) 1.5679(18) 115.97(9) 115.78(9) 119.35(9) 123.67(11) 120.64(12) 119.82(10) 123.16(11) 119.76(12) 123.31(11) 114.77(9) 119.29(9) 119.12(9) 0.1752(15) Planar 0.0868(19) (N3) 0.0528(19) (N8) 0.197(3) (C2)

Max. deviation for 5-membered rings

*

115.40(7) 119.18(8) 119.57(8) 122.94(9) 119.70(9) 122.47(6)

0.0606(11)

115.63(9) 116.10(10) 119.81(9) 124.21(11) 121.70(11) 120.63(11)

0.1443 0.1004 (P1) 0.1943 (C1)

115.73(11) 116.21(11) 117.09(11) 123.68(13) 122.24(13) 122.96(13)

0.1224 0.0783 (N2) 0.1517 (C1) 0.0989 (C4)

The compound has a center of symmetry.

preparation of new cyclic P–N derivatives like cyclotriphosphazene and cyclotetraphosphazene. The other particular interest was in the disubstituted derivatives, to see if the second nucleophile would go on the same ring as the first, the other ring or a statistical mixture of both. 31P

NMR analysis of the reaction mixture is very useful to elucidate this situation. The 31P NMR spectrum of the reaction mixture of compound 1 with disodium 1,2-ethanediol at a 1:2 molar ratio showed (Fig. 9) the relative amounts of formation of the di-spiro derivatives 3–5. Whereas the ipsilateral di-spiro isomer (4) formed

S. Besßli et al. / Polyhedron 98 (2015) 230–237

237

Fig. 9. Proton-decoupled 31P NMR spectrum of the reaction mixture of compound 1 with the disodium salt of 1,2-ethanediol in a 1:2 ratio in THF solution; the reaction mixture was filtered and the solvent removed prior to dissolving in CDCl3 solution.

in 30% yield, the different side isomers, in which the spiro groups were trans (3) or cis (5) to each other, formed in 37% yield. In this case there is no preference for the second nucleophile attacking either the same ring or the other ring. However the trans isomer (3) is the predominant product for the different side isomers. 4. Conclusion In this study, the first nucleophilic substitution reactions of N,Nspiro bridged octachlorobiscyclotriphosphazene are reported. The reactions of the compound 1 with 1,2-ethanediol at different molar ratios gave five different types of products, whose structures were characterized by elemental analysis, mass spectrometry, 1H and 31 P NMR spectroscopy and X-ray crystallography; mono-spiro compound (2), trans di-spiro compound (3), ipsilateral di-spiro compound (4), cis di-spiro compound (5) and tetra-spiro compound (6). The interesting 31P NMR spectra were recorded and these spectra can be used as a guide to characterize the similar compounds. Furthermore, we report the first X-ray crystallographic characterization of all the compounds. Acknowledgements The authors would like to thank the Scientific and Technical Research Council of Turkey for financial support (Grant 113Z304) and Professor Christopher W. Allen (Department of Chemistry, University of Vermont) for helpful discussions. Appendix A. Supplementary data CCDC 1051498, 1051499, 1051500, 1051502 and 1051502 contain the supplementary crystallographic data for compounds 2, 3, 4, 5 and 6, respectively. These data can be obtained free of charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223–336-033; or e-mail: [email protected].

[5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25]

[26]

[27] [28] [29] [30] [31] [32] [33] [34] [35] [36]

[37]

References [1] C.W. Allen, Chem. Rev. 91 (1991) 119. [2] V. Chandrasekhar, P. Thilagar, M. Pandian, Coord. Chem. Rev. 251 (2007) 1045. [3] M. Gleria, R. De Jaeger (Eds.), Applicative Aspects of Cyclophosphazenes, Nova Science Publishers, New York, 2004. [4] V. Chandrasekhar, G.T.S. Andavan, R. Azhakar, B.M. Pandian, Tetrahedron Lett. 47 (2006) 8365.

[38] [39] [40]

V. Chandrasekhar, S. Nagendran, Chem. Soc. Rev. 30 (2001) 193. M. Bahadur, C.W. Allen, W.E. Geiger, A. Bridges, Can. J. Chem. 80 (2002) 1393. M. Calichman, A. Derecskei-Kovacs, C.W. Allen, Inorg. Chem. 46 (2007) 2011. C.N. Myer, C.W. Allen, Inorg. Chem. 41 (2002) 60. B.A. Omotowa, B.S. Phillips, J.S. Zabinski, J.M. Shreeve, Inorg. Chem. 43 (2004) 5466. M.S. Kumar, R.P. Gupta, A.J. Elias, Inorg. Chem. 47 (2008) 3433. R. Boomishankar, P.I. Richards, A.K. Gupta, A. Steiner, Organometallics 29 (2010) 2515. S.S. Krishnamurthy, Indian Nat. Sci. Acad. 52A (4) (1986) 1020. K. Keshav, N. Singh, A.J. Elias, Inorg. Chem. 49 (2010) 5753. D. Kumar, N. Singh, K. Keshav, A.J. Elias, Inorg. Chem. 50 (2011) 250. K. Muralidharan, B.A. Omotowa, B. Twamley, C. Piekarski, J.M. Shreeve, Chem. Commun. (2005) 5193. P.I. Richards, A. Steiner, Inorg. Chem. 44 (2005) 275. K.R. Carter, M. Calichman, C.W. Allen, Inorg. Chem. 48 (2009) 7476. S. Besßli, S.J. Coles, D.B. Davies, A.O. Erkovan, M.B. Hursthouse, A. Kılıç, Inorg. Chem. 47 (2008) 5042. S. Besßli, S.J. Coles, D.B. Davies, A. Kılıç, R.A. Shaw, Dalton Trans. 40 (2011) 5307. A.H. Alkubaisi, H.G. Parkes, R.A. Shaw, Heterocycles 28 (1989) 347. S. Besßli, S.J. Coles, D. Davarcı, D.B. Davies, F. Yuksel, Polyhedron 30 (2011) 329. S. Besßli, S.J. Coles, D.B. Davies, A.O. Erkovan, M.B. Hursthouse, A. Kılıç, Polyhedron 28 (2009) 3593. K. Muralidharan, A.J. Elias, Inorg. Chem. 42 (2003) 7535. H.R. Allcock, U. Diefenbach, S.R. Pucher, Inorg. Chem. 33 (1994) 3091. K. Brant, I. Porwolik-Czomperlik, M. Siwy, T. Kupka, R.A. Shaw, S. Ture, A. Clayton, D.B. Davies, M.B. Hursthouse, G.D. Sykara, J. Org. Chem. 64 (1999) 7299. D.B. Davies, T.A. Clayton, R.E. Eaton, R.A. Shaw, A. Eagen, M.B. Hursthouse, G.D. Sykara, I. Porwolik-Czomperlik, M. Siwy, K. Brant, J. Am. Chem. Soc. 122 (2000) 12447. S. Besßli, S.J. Coles, D.B. Davies, R.J. Eaton, M.B. Hursthouse, A. Kılıç, R.A. Shaw, Polyhedron 25 (2006) 963. S. Besßli, S.J. Coles, D. Davarcı, D.B. Davies, M.B. Hursthouse, A. Kılıç, Polyhedron 26 (2007) 5283. K. Brandt, T. Kupka, J. Drodz, J.C. Van de Grampel, A. Meetsma, A.P. Jekel, Inorg. Chim. Acta 228 (1995) 187. G.A. Carriedo, F.J. Garcia-Alonso, J.L. Garcia-Alvarez, G.C. Pappalardo, F. Punzo, P. Rossi, Eur. J. Inorg. Chem. 13 (2003) 2413. E.W. Ainscough, A.M. Brodie, A. Derwahl, S. Kirk, C.A. Otter, Inorg. Chem. 46 (2007) 9841. Bruker, SADABS, Bruker AXS Inc., Madison, Wisconsin, USA, 2005. Bruker APEX2 (Version 2011.4-1). Bruker AXS Inc., Madison, Wisconsin, USA, 2008. G.M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112. A.L. Spek, Acta Crystallogr., Sect. D 65 (2009) 148. C.F. Macrae, I.J. Bruno, J.A. Chisholm, P.R. Edgington, P. McCabe, E. Pidcock, L. Rodriguez-Monge, R. Taylor, J. van de Streek, P.A. Wood, J. Appl. Crystallogr. 41 (2008) 466. K. Brandenburg, DIAMOND 3.1 for Windows. Crystal Impact GbR, Bonn, Germany, 2006. S.R. Contractor, M.B. Hursthouse, L.S. Shaw, R.A. Shaw, H. Yılmaz, Acta Crystallogr., Sect. B 41 (1985) 122. E. Tanrıverdi Ecik, S. Besßli, G. Yenilmez Ciftci, D.B. Davies, A. Kılıc, F. Yuksel, Dalton Trans. 41 (2012) 6715. V. Chandrasekhar, S.S. Krishnamurthy, H. Manohar, A.R.V. Murthy, R.A. Shaw, M. Woods, J. Chem. Soc., Dalton Trans. (1984) 621.