Synthesis and reactivity of rare-earth metal phosphaethynolates

Transcription

1 Electronic Supplementary Material (ESI) for Dalton Transactions. This journal is The Royal Society of Chemistry 28 Supporting Information Synthesis and reactivity of rare-earth metal phosphaethynolates Sebastian Bestgen, Qien Chen, Nicholas H. Rees, and Jose M. Goicoechea* Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 2 Mansfield Road, Oxford, OX 3TA, U.K. jose.goicoechea@chem.ox.ac.uk I. Characterization...2 II. Materials and general synthetic procedures...3 III. Synthesis of metal complexes...4 IV. X-ray crystallography... V. NMR Spectra...8 References...35 S.I.

2 I. Characterization General synthetic methods All reactions and product manipulations were carried out under an inert atmosphere of argon or dinitrogen using standard Schlenk-line or glovebox techniques (MBraun UNIlab glovebox maintained at <. ppm H 2 O and <. ppm O 2 ). Nuclear Magnetic Resonance (NMR) NMR samples were prepared inside an inert atmosphere glovebox in NMR tubes fitted with a gas-tight valve. H, B, 3 C{ H}, 9 F, and 3 P{ H} NMR spectra were recorded on the following NMR instruments with appropriate resonance frequencies: a) Bruker Avance III HD nanobay NMR equipped with a 9.4 T magnet ( H 4.2 MHz, B 28.4 MHz, 3 C.6 MHz, 9 F MHz, 3 P 62. MHz), b) Bruker Avance III NMR equipped with a.75 T magnet ( H MHz, B 6.4 MHz, 3 C 25.7 MHz, 9 F 47.4 MHz, 3 P 22.4 MHz), c) Bruker Avance NMR equipped with a.75 T magnet and a 3 C detect cryoprobe ( H 5.3 MHz, 3 C 25.8 MHz). 89 Y{ H} INEPT and H-{ 89 Y} HMQC NMR spectra were recorded at 9.6 MHz and (4.2 MHz / 9.6 MHz), respectively, on the Bruker Avance III HD nanobay NMR. H and 3 C{ H} NMR spectra are reported relative to TMS and referenced to the most downfield residual solvent resonance where possible. 3 P{ H} NMR spectra were externally referenced to an 85% solution of H 3 PO 4 in H 2 O (δ = ppm). 89 Y{ H} NMR spectra were externally referenced to a M solution of Y(NO 3 ) 3 (H 2 O) 6 in D 2 O. Infrared (IR) Spectroscopy IR spectra were obtained on a Bruker Tensor 37 as Nujol mulls. Elemental Analysis (EA) Elemental analyses were carried out by Elemental Microanalyses Ltd. (Devon, U. K.). Samples (approx. mg) were submitted in sealed Pyrex ampoules. S.I. 2

3 II. Materials and general synthetic procedures n-pentane, n-hexane (hex; Sigma-Aldrich, HPLC grade), benzene and toluene (Sigma-Aldrich; HPLC grade) were purified using an MBraun SPS-8 solvent system. Tetrahydrofuran (thf; Sigma-Aldrich, HPLC grade) was distilled over sodium metal/benzophenone. All dry solvents were stored under argon in gas-tight ampoules. Additionally, n-pentane, n-hexane and thf were stored over activated 3 Å molecular sieves. thf-d 8 (Sigma-Aldrich, 99.5%) was dried over CaH 2 and vacuum distilled before use. C 6 D 6 was stored over activated 3 Å molecular sieves and degassed prior to use. Potassium bis(trimethylsilyl)amide (KHMDS) was purchased from Sigma Aldrich (95 %) and used as received. Anhydrous YCl 3 and NdCl 3 were purchased from Strem chemicals and used as received. Sm metal was obtained from smart-elements GmbH (Austria). [Na(OCP)(dioxane) x ] (x = 3.42, 2 or.3) was prepared according to literature procedures. [] The dioxane content was determined by 3 P{ H} NMR spectroscopy using PPh 3 as internal standard. B(C 6 F 5 ) 3 was prepared according to literature procedures. [2] N, N'-bis(2,6-diisopropylphenyl)formamidine (DippFormH), [3] SmI 2 (thf) 2, [4] and [(DippForm) 2 Sm(thf) 2 ] [5-6] were prepared according to literature procedures. DippFormK was reported previously using a slightly different procedure. [7] S.I. 3

4 III. Synthesis of metal complexes Synthesis of [(DippForm)K] To a mixture of N,N'-bis(2,6-diisopropylphenyl)formamidine (4. g,.97 mmol,. eq.) and KHMDS (2.4 g, 2.8 mmol,. eq.), toluene (5 ml) was added. The cloudy suspension was stirred at room temperature for 4 hours before the solvent was removed by filtration. The resulting solid residue was washed with toluene (3 ml) and dried thoroughly under vacuum for 2 hours to yield the product as colorless powder. The compound was used for subsequent reactions without further purification. Yield: g (98 %). H NMR (4.2 MHz, thf-d 8 ): δ [ppm] =. (d, 3 J H H = 6.9 Hz, 24H, CHMe 2 ), 3.62 (sept, 3 J H H = 6.9 Hz, overlapping with solvent peak, 4H, CHMe 2 ), 6.64 (t, 3 J H H = 7.6 Hz, 2H, p-ch), 6.87 (d, 3 J H H = 7.6 Hz, 4H, m-ch), 7.49 (s, H, NCHN). 3 C{ H} NMR (25.8 MHz, thf-d 8 ): δ [ppm] = 24.9 (CHMe 2 ), 28.3 (CHMe 2 ), 9.9 (p-c), 22.7 (m- C), 42.5 (o-c), 54. (ipso-c), 63.2 (NCHN). Synthesis of [(DippForm) 2 YCl(thf)] (A) [(DippForm)K] (.275 g, 3.7 mmol, 2. eq.) and anhydrous YCl 3 (39 mg,.58 mmol,. eq.) were added to a Schlenk tube and dissolved in thf (2 ml). After stirring at 5-6 C overnight, the solvent was removed under vacuum and the residue was extracted with toluene (2 x ml). After filtration using a filter cannula, a clear colorless solution was obtained, which was concentrated until incipient precipitation occurred. Colorless crystals suitable for single crystal X-ray diffraction were obtained from a saturated toluene solution at room temperature. Yield: 765 mg (52 %, single crystals). H NMR (5.3 MHz, C 6 D 6 ): δ [ppm] =.75 (m, 4H, OCH 2 CH 2 (thf)),.9 (d, 3 J H H = 6.8 Hz, 48H, CHMe 2 ), 3.66 (m, overlapping, 2H, CHMe 2 and OCH 2 (thf)), (m, 2H, CH), 8.7 (d, 3 J H Y = 3.6 Hz, 2H, NCHN). 3 C{ H} NMR (25.8 MHz, C 6 D 6 ): δ [ppm] = 23.4 (CHMe 2 ), 25. (OCH 2 CH 2 (thf)), 26.8 (CHMe 2 ), 28.5 (CHMe 2 ), 7.4 (OCH 2 (thf)), 23.9 (m-c), 25.3 (p-c), 43.9 (o-c), 45. (ipso-c), 7.6 (d, 2 J C-Y = 3.3 Hz, NCHN). 89 Y{ H} INEPT NMR (9.6 MHz, C 6 D 6 ): δ [ppm] = H-{ 89 Y} HMQC NMR ((4.2 MHz / 9.6 MHz), C 6 D 6 ): δ [ppm] = 8.7 / S.I. 4

5 IR (Nujol, cm ): 668 (w), 593 (w), 525 (s), 46 (s), 378 (s), 39 (w), 276 (s), 26 (m), 94 (w), 97 (m), 57 (m), 45 (m), 7 (m), 945 (w), 862 (w), 8 (m), 775 (w), 758 (w), 722 (w), 672 (w). Synthesis of [(DippForm) 2 NdCl(thf)] (B) [(DippForm)K] (.56 g, 3.87 mmol, 2. eq.) and anhydrous NdCl 3 (486 mg,.93 mmol,. eq.) were added to a Schlenk tube and dissolved in thf (2 ml). After stirring at 5-6 C overnight, the solvent was removed under vacuum and the residue was extracted with toluene (2 x ml). After filtration using a filter cannula, a clear blueish solution was obtained, which was concentrated until incipient precipitation occurred. The suspension was heated until a clear solution was obtained. Overnight, a small amount of microcrystalline precipitate formed, which was separated from the mother liquor by filtration and discarded. Storing the so obtained solution at ambient temperature afforded large blueish-purple crystals within 48 hours, which were isolated and dried under vacuum. A second crop of crystals was obtained by further concentrating the mother liquor and storage for a week. Yield: 92 mg (5 %, single crystals). H NMR (4.2 MHz, C 6 D 6 ): δ [ppm] = 3.4,.34, 2.32, 7.66, 9.4, Due to the paramagnetic nature of B, only broad and unstructured resonances were observed. IR (Nujol, cm ): 665 (m), 592 (w), 523 (s), 362 (m), 36 (m), 279 (s), 26 (m), 234 (w), 9 (m), 77 (m), 6 (w), 8 (m), 97 (m), 56 (w), 43 (w), 6 (m), 942 (w), 934 (w), 863 (w), 8 (m), 775 (m), 757 (m), 757 (m), 722 (m). Elemental analysis calcd (%) for [C 54 H 78 ClN 4 NdO] ( g/mol): C 66.25, H 8.3, N 5.72; found C 66.8, H 8.9, N Synthesis of [(DippForm) 2 Y(OCP)(thf)] () The complex [(DippForm) 2 YCl(thf)] (A) (3 mg,.33 mmol,. eq.) and [Na(OCP)(dioxane) 3.42 ] (3 mg,.33 mmol,. eq.) were dissolved in thf ( ml) and stirred overnight. The solvent was then removed under vacuum and the residue was extracted with toluene ( ml) and filtered. Upon concentration of the organic phase, colorless crystals formed after 2 days and were separated from the mother liquor by decantation. Yield: 36 mg (44 %, single crystals). H NMR (5.3 MHz, C 6 D 6 ): δ [ppm] =.82 (m, 4H, OCH 2 CH 2 (thf)),.2 (bs, 48H, CHMe 2 ), 3.46 (hept, 3 J H-H = 6.9 Hz, 8H, CHMe 2 ), 3.74 (m, 4H, OCH 2 (thf)), (m, 2H, CH), 8.2 (d, 3 J H-Y = 3.9 Hz, 2H, NCHN). S.I. 5

6 3 C{ H} NMR (25.8 MHz, C 6 D 6 ): δ [ppm] = 23.8 (CHMe 2 ), 25. (OCH 2 CH 2 (thf)), 26.7 (CHMe 2 ), 28.9 (CHMe 2 ), 7. (OCH 2 (thf)), 23.8 (m-c), 25.5 (p-c), 43.6 (o-c), 44.5 (d, 2 J C Y =.3 Hz, ipso-c), 56. (dd, J C P = 7.3 Hz, 2 J C Y = 4.4 Hz, OCP), 72. (d, 2 J C Y = 3.4 Hz, NCHN). 3 P{ H} NMR (62. MHz, C 6 D 6 ): δ [ppm] = Y{ H} INEPT NMR (9.6 MHz, C 6 D 6 ): δ [ppm] = (s). H-{ 89 Y} HMQC NMR ((4.2 MHz / 9.6 MHz), C 6 D 6 ): δ [ppm] = 8.2 / IR (Nujol, cm ): 69 (OCP), 668 (w), 52 (m), 46 (s), 377 (s), 36 (w), 272 (m), 9 (w), 98 (m), 56 (b), 923 (w), 865 (w), 8 (w), 757 (w), 72 (w), 667 (w). Elemental analysis calcd (%) for [C 55 H 78 N 4 O 2 PY] (947.3 g/mol): C 69.75, H 8.3, N 5.92; found C 69.25, H 8.32, N Synthesis of [(DippForm) 2 Nd(OCP)((thf)] (2) The complex [(DippForm) 2 NdCl(thf)] (B) (64 mg,.6 mmol,. eq.) and [Na(OCP)(dioxane) 3.42 ] (75 mg,.9 mmol,.2 eq.) were dissolved in thf ( ml) and stirred overnight at 5 C. The solvent was then removed under vacuum and the residue was extracted with toluene ( ml) and filtered. Upon concentration of the organic phase, colorless crystals formed after 2 days and were separated from the mother liquor by decantation. Yield: 9 mg (57 %, single crystals). H NMR (4.2 MHz, C 6 D 6 ): δ [ppm] = 3.6, 2.37,.5,.78, 2.28, 6.8, 7.52, 8.88, 4.76, Due to the paramagnetic nature of 2, only broad and unstructured resonances were observed. 3 P{ H} NMR (62. MHz, C 6 D 6 ): δ [ppm] = IR (Nujol, cm ): 685 (w, OCP), 667 (m), 59 (w), 363 (m), 36 (w), 278 (m), 26 (s), 234 (w), 89 (w), 95 (br), 9 (br), 943 (w), 862 (w), 8 (s), 757 (m), 72 (w). Elemental analysis calcd (%) for [C 55 H 78 N 4 NdO 2 P] (2.47 g/mol): C 65.9, H 7.84, N 5.59; found C 65.84, H 7.8, N Synthesis of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) To a mixture of [(DippForm) 2 YCl(thf)] (A) (4 mg,.43 mmol,. eq.) and [Na(OCP)(dioxane).3 ] (95 mg,.86 mmol, 2. eq.), thf ( ml) was added. The resulting light-yellow suspension was stirred at room temperature for two hours before all volatiles were removed under vacuum. 8-crown-6 (4 mg,.43 mmol,. eq.) was added to the solid residue followed by thf ( ml). The cloudy suspension was stirred at room temperature overnight. The precipitate was separated from the solution by cannula filtration. Upon addition of n-hexane, the product precipitated from the thf solution as a colourless powder (343 mg, 55% crude yield). Because the powder slowly decomposed when it was S.I. 6

7 dried under vacuum, an aliquot (5 mg) was redissolved in thf and layered with n-hexane for further purification. Colourless crystals suitable for single crystal X-ray diffraction were obtained within days. H NMR (5.3 MHz, thf-d 8 ): δ [ppm] =.8 (d, 3 J H H = 6.8 Hz, 48H, CHMe 2 ),.77 (m, OCH 2 CH 2 (thf)), 3.43 (m, fluxional, 4H, CHMe 2 ), 3.62 (m, overlapping, OCH 2 (thf)), 3.62 (m, overlapping, 24H, OCH 2 CH 2 O (8-crown-6)), 3.85 (m, fluxional, 4H, CHMe 2 ), 6.85 (m, fluxional, 2H, aromatic H), 7.8 (d, 3 J H Y = 3. Hz, 2H, NCHN). VT H NMR (4.2 MHz, thf-d 8, 333K): δ [ppm] =.9 (d, 3 J H H = 6.7 Hz, 24H, CHMe 2 ),.2 (d, 3 J H H = 6.7 Hz, 24H, CHMe 2 ),.77 (m, OCH 2 CH 2 (thf)), 3.63 (m, overlapping, 8H, CHMe 2 ), 3.63 (m, overlapping, OCH 2 (thf)), 3.63 (m, overlapping, 24H, OCH 2 CH 2 O (8-crown-6)), 6.8 (t, 3 J H H = 7.6 Hz, 4H, p-ch), 6.9 (d, 3 J H H = 7.6 Hz, 8H, m-ch), 7.82 (d, 3 J H Y = 3. Hz, 2H, NCHN). 3 C{ H} NMR (25.8 MHz, thf-d 8 ): δ [ppm] = 24.5 (br, fluxional, CHMe 2 ), 26.6 (OCH 2 CH 2 (THF)), 28.5 (br, fluxional, CHMe 2 ), 68.4 (OCH 2 (thf)), 7.9 (OCH 2 CH 2 O (8-crown-6)), 23.5 (br, fluxional, aromatic C), 6.4 (dd, J C P = 8. Hz, 2 J C Y = 3.7 Hz, OCP), 7.4 (d, 2 J C Y = 3. Hz, NCHN). 3 P{ H} NMR (62. MHz, thf-d 8 ): δ [ppm] = Y{ H} INEPT NMR (9.6 MHz, thf-d 8 ): δ [ppm] = 47.3 ppm. H-{ 89 Y} HMQC NMR ((4.2 MHz / 9.6 MHz), thf-d 8 ): δ [ppm] = 7.8 / IR (Nujol, cm ): 799 (w), 77 (w, OCP), 6 (b), 463 (s), 377 (s), 3 (w), 26 (w), 238 (w), 52 (w), 93 (m), 2 (w), 944 (w), 8 (w), 722 (w). Elemental analysis calcd (%) for [C 76 H 8 N 4 NaO P 2 Y] ( g/mol): No satisfactory results could be obtained. Synthesis of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Nd(OCP) 2 (thf)] (4) To a mixture of [(DippForm) 2 NdCl(thf)] (A) (2 mg,.2 mmol,. eq.) and [Na(OCP)(dioxane).3 ] (47 mg,.43 mmol, 2.5 eq.), thf ( ml) was added. The resulting lightyellow suspension was stirred at room temperature for two hours before all volatiles were removed under vacuum. 8-crown-6 (57 mg,.2 mmol,. eq.) was added to the solid residue followed by thf ( ml). The cloudy suspension was stirred at room temperature overnight and subsequently filtered. The thf solution was concentrated and layered with n-hexane, which ultimately led to the formation of colorless (light bluish) crystals, which partially decompose over time. The mother liquor was removed via decantation and the crystalline residue was shortly dried under vacuum. Yield: 8 mg (58 %). Fresh samples can be crystallized from crude product. S.I. 7

8 H NMR (4.2 MHz, thf-d 8 ): δ [ppm] = 2.86 (bs),.4 (bs),.9 (s), 4.6 (bs, crown, thf), 5.72 (bs), 7.66 (bs), 9.3 (bs), 2.93 (bs), 2. (bs). Due to the paramagnetic nature of 4, only broad and unstructured resonances were observed. 3 P{ H}NMR (62. MHz, thf-d 8 ): δ [ppm] = IR (Nujol, cm ): 72 (s), 683 (s, OCP), 59 (w), 525 (s), 35 (m), 37 (m), 284 (m), 247 (m), 9 (m), 9 (s), 54 (w), 964 (m), 937 (w), 844 (m), 8 (w), 772 (w), 756 (w), 722 (w). Elemental analysis calcd (%) for [C 76 H 8 N 4 NaNdO P 2 ] ( g/mol): No satisfactory results could be obtained. Synthesis of [(DippForm) 2 Nd(μ 2 -OCP)] 2 (5) [(DippForm) 2 Nd(OCP)((thf)] (2) (59 mg,.58 mmol,. eq.) and B(C 6 F 5 ) 3 (3 mg,.58 mmol,. eq.) were added to an NMR or Schlenk tube and dissolved in benzene ( 2 ml). The pale blueish mixture was shaken until a clear solution was obtained and left standing for at two days. Light blue block-like crystals were obtained and separated from the mother liquor by decantation. The crystals were quickly washed with small amounts of benzene and dried under vacuum. Yield: 42 mg (78 %, single crystals). H NMR (4.2 MHz, thf-d 8 ): δ [ppm] =.9 (bs),.9 (bs), 3.4 (bs), 7. (bs), 8.3 (bs), 29.4 (s). Due to the paramagnetic nature of 5, only broad and unstructured resonances were observed. 3 P{ H} NMR (62. MHz, thf-d 8 ): δ [ppm] = IR (Nujol, cm ): 748 (m, OCP), 363 (w), 26 (m), 56 (m), 94 (br), 2 (br), 8 (s), 72 (w). Elemental analysis calcd (%) for [C 2 H 4 N 8 Nd 2 O 2 P 2 ] (86.73 g/mol): C 65.84, H 7.58, N 6.2; found 65.42, H 7.27, N Synthesis of [(DippForm)Sm(8-crown-6)(thf)][DippForm] (6) [(DippForm) 2 Sm(thf) 2 ] (5 mg,.4 mmol,. eq.) and 8-crown-6 (3 mg,.4 mmol,. eq.) were dissolved in thf (.6 ml) in an J. Young NMR tube and shaken until a clear green solution was obtained. The mixture was concentrated to approximately.2 ml and layered with n-hexane. Dark green crystals were obtained within a few days, separated from the mother liquor by decantation and dried under vacuum. Yield: 35 mg (6 %, single crystals). H NMR (4.2 MHz, thf-d 8 ): δ [ppm] = 9.58,.47, 3.62, 3.66, 5.32, 6.79, Due to the paramagnetic nature of 6, only broad and unstructured resonances were observed. S.I. 8

9 IR (Nujol, cm ): 2723 (w), 59 (w), 54 (m), 342 (w), 33 (m), 236 (w), 8 (w), 54 (vw), 85 (m), 38 (w), 96 (w), 92 (vw), 896 (vw), 837 (vw), 777 (vw), 767 (vw), 757 (w), 72 (w). Elemental analysis calcd (%) for [C 66 H 2 N 4 O 7 Sm] (23.92 g/mol): C 65.3, H 8.47, N 4.62; found 64.76, H 8.44, N Synthesis of [(DippForm)Sm(OCP)(8-crown-6)] (7) [(DippForm) 2 Sm(thf) 2 ] ( mg,. mmol,. eq.) and 8-crown-6 (26 mg,. mmol,. eq.) were dissolved in thf (2 ml) in an J. Young tube and stirred until a clear green solution was obtained (~ 2 hours). Subsequently, a solution of [Na(OCP)(dioxane).3 ] ( mg,. mmol,. eq.) in thf ( ml) was added to the reaction mixture, which was stirred for another 4 hours. The clear dark green solution was layered with n-hexane (25 ml) and left standing until dark green crystals formed (4 7 days). The crystals were isolated by decantation from the mother liquor and dried under vacuum. Yield: 42 mg (5 %, single crystals). Note: After prolonged periods, the formation of colorless blocklike crystals is also observed, which were found to be the oxidized species [Na(8-crown- 6)(thf) 2 ][(DippForm) 2 Sm(OCP) 2 (thf)] (7b, See crystallographic section for the structure). H NMR (4.2 MHz, C 6 D 6 ): δ [ppm] = 9.6 (bs; 2H, NCHN),.33 (bs, 2H, CH 3 ), 3.9 (bs, overlapping, 6H, CH 3 and CH(CH 3 ) 2 ), 4.9 (d, 3 J H-H = 7.2 Hz, 4H, m-ch), 6.29 (t, 3 J H-H = 7.2 Hz, 2H, p-ch), 6.56 (bs, 2H, CH 2 ), 8.5 (bs, 2H, CH 2 ). 3 C{ H} NMR (25.8 MHz, C 6 D 6 ): δ [ppm] = 22.9, 24.5, 35.6, 4.9, 5.8, 2.6, 24.5, P{ H} NMR (62. MHz, C 6 D 6 ): δ [ppm] = IR (Nujol, cm ): 758 (m, OCP), 666 (w), 592 (vw), 526 (m), 326 (w), 295 (m), 258 (w), 83 (w), 99 (m), 79 (m), 995 (vw), 965 (w), 876 (vw), 838 (w), 82 (w), 763 (w), 72 (w). Elemental analysis calcd (%) for [C 38 H 59 N 2 O 7 Sm] ( g/mol): C 54.52, H 7., N 3.35; found 53.92, H 7.22, N 3.2. Synthesis of [(DippForm)Sm(2,2,2-crypt)][DippForm] (8) [(DippForm) 2 Sm(thf) 2 ] (45 mg,.4 mmol,. eq.) and 2,2,2-crypt (6 mg,.4 mmol,. eq.) were dissolved in thf (.6 ml) in an J. Young NMR tube and shaken until a clear red solution was obtained. The mixture was concentrated to approximately.2 ml and left standing overnight. Large dark-red crystals formed which were separated from the mother liquor by decantation and subsequently washed with thf (2.5 ml) and dried under vacuum. Yield: 4 mg (8 %, single crystals). S.I. 9

10 H NMR (4.2 MHz, thf-d 8 ): δ [ppm] = 9.95, 2.5, 2.39,.8,.4,.,.4,.6,.52, 2.92, 4.4, 6.2, 7.3, 8.3, 8.78, Due to the paramagnetic nature of 8, only broad and unstructured resonances were observed. IR (Nujol, cm ): 592 (w), 377 (w), 3 (w), 342 (w), 259 (w), 235 (w), 8 (w), 92 (w), 63 (w), 8 (w), 82 (w). Elemental analysis calcd (%) for [C 68 H 6 N 6 O 6 Sm] ( g/mol): C 65.3, H 8.52, N 6.7; found C 65., H 8.49, N 6.4. Synthesis of [(2,2,2-crypt)Sm(OCP) 2 ](9) A mixture of [(DippForm) 2 Sm(thf) 2 ] ( mg,. mmol,. eq.) and 2,2,2-crypt (37 mg,. mmol,. eq.) was dissolved in thf (2 ml) inside the glovebox. The solution was left standing at room temperature for 2 hours and during this period, a colour change of the solution from green to red was observed. [Na(OCP)(dioxane).3 ] (22 mg,.2 mmol, 2. eq.) was added to the solution as a solid, and red crystals suitable for single crystal X-ray diffraction rapidly formed. Yield: 3 mg (47 %, single crystals). H NMR (5.3 MHz, d 5 -pyridine): δ [ppm] =.46 (s, 2H, NCH 2 ), 3.26 (s, 2H, OCH 2 CH 2 O), 3.58 (s, 2H, NCH 2 CH 2 O). 3 C{ H} NMR (25.8 MHz, d 5 -pyridine): δ [ppm] = 92.4 (NCH 2 ), 99.4 (NCH 2 CH 2 O), 99.6 (OCH 2 CH 2 O), 83.9 (d, J C P = 48.4 Hz, OCP). 3 P{ H} NMR (62. MHz, d 5 -pyridine): δ [ppm] = 374. (s). IR (Nujol, cm ): 782 (w), 763 (PCO), 749 (PCO), 623 (b), 463 (s), 377 (s), 35 (w), 32 (w), 26 (w), 25 (m), 9 (m), 66 (m), 3 (b), 957 (w), 8 (w), 722 (w), 668 (w). Elemental analysis calcd (%) for [C 2 H 36 N 2 O 8 P 2 Sm] ( g/mol): C 37.25, H 5.63, N 4.34; found C 37.39, H 5.62, N 4.3. S.I.

11 IV. X-ray crystallography Single crystal X-ray structure determination: Single-crystal X-ray diffraction data were collected using an Oxford Diffraction Supernova dual-source diffractometer equipped with a 35 mm Atlas CCD area detector. Crystals were selected under Paratone-N oil, mounted on micromount loops and quenchcooled using an Oxford Cryosystems open flow N 2 cooling device. [8] Data were collected at 5 K using mirror monochromated Cu Kα radiation (λ =.548 Å; Oxford Diffraction Supernova). Data collected on the Oxford Diffraction Supernova diffractometer were processed using the CrysAlisPro package, including unit cell parameter refinement and inter-frame scaling (which was carried out using SCALE3 ABSPACK within CrysAlisPro). [9] Equivalent reflections were merged and diffraction patterns processed with the CrysAlisPro suite. Structures were subsequently solved using direct methods and refined on F 2 using the ShelXL 23 package and ShelXle. [][] Crystallographic data for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as a supplementary publication No Copies of the data can be obtained free of charge on application to CCDC, 2 Union Road, Cambridge CB2EZ, UK (fax: (+(44) ; deposit@ccdc.cam.ac.uk). S.I.

12 Figure S: Molecular structure of [(DippForm) 2 Y(OCP)(thf)] () in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Y-O 2.562(2), Y-N 2.353(3), Y-N (4), Y-N (3), Y-N (3), Y-OS (), P-C.559(2), C-O.25(2); O-C-P 78.5(2), N-Y-N2 57.3(5), O-Y-N4 34.3(5), O-Y-N 7.44(5), O- Y-N2 5.65(5). Figure S2: Molecular structure of [(DippForm) 2 Nd(OCP)(thf)] (2) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Nd-N 2.495(3), Nd-N (3), Nd-N (3), Nd-N4 2.48(3), Nd-O 2.224(3), Nd-OS 2.47(3), P-C.557(6), C-O.252(6); O-Nd-N 5.(2), O-Nd-N3 25.4(3), O-Nd-N2 8.9(3), N-Nd-N (), N3- Nd-N (), O-C-P 77.3(5). S.I. 2

13 Figure S3: Molecular structure of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Y-O 2.22(2), Y-O (2), Y-N 2.43(2), Y-N (2), Y-N (2), Y-N4 2.4(2), O-C.227(3), C-P.57(3), O2-C2.229(3), C2-P2.57(3), O-Y-O2 73.6(7), C-O-Y 64.2(2), O-C-P 79.2(3), C2- O2-Y 62.5(2), O2-C2-P2 79.2(2). Figure S4: Molecular structure of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Nd(OCP) 2 (thf)] (4) in the solid state. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Nd-O 2.36(5), Nd-O (5), Nd-N 2.5(2), Nd-N2 2.58(2), Nd-N3 2.5(2), Nd-N (2), O-C.234(3), C-P.562(3), O2-C2.24(3), C2-P2.562(2); O- Nd-O2 7.96(6), N-Nd-N (5), N4-Nd-N (5), O-C-P 78.9(2), O2-C2-P2 79.(2). S.I. 3

14 Figure S5: Molecular structure of [(DippForm) 2 Nd(μ 2 -OCP)] 2 (5) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Nd-O 2.352(3), Nd-N 2.468(3), Nd-N2 2.43(4), Nd-N (4), Nd-N4 2.45(3), Nd-P 3.58(2), O-C.234(5), C-P.582(4); O-C-P 76.(4), N-Nd-N2 55.3(), N3-Nd-N (), O-Nd-N 9.6(2), O-Nd- N2 9.72(2), O-Nd-N3 3.42(), O-Nd-N4 95.3(). Figure S6: Molecular structure of [(DippForm)Sm(8-crown-6)(thf)][DippForm] (6) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Sm-N 2.77(4), Sm-N (4), N3- C26.37(7), N4-C26.39(7); N2-Sm-N 5.7(3), OS-Sm-N 52.92(4), N2-Sm-OS 52.39(4), N3-C26-N4 28.9(5). S.I. 4

15 Figure S7: Molecular structure of [(DippForm)Sm(OCP)(8-crown-6)] (7) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Sm-O 2.6(3), Sm-N 2.642(3), Sm-N (3), Sm-O 2.765(3), Sm-O (3), Sm-O3 2.65(3), Sm-O (3), Sm-O5 2.78(3), Sm-O6 2.76(3), P-C.586(4), C-O.29(5); O-Sm-N 55.2(9), O-Sm-N (9), N-Sm-N2 5.32(8), O-C-P 78.4(3). Figure S8: Molecular structure of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Sm(OCP) 2 (thf)] (7B) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Sm-O 2.299(2), Sm- O (2), Sm-O (2), Sm-N 2.499(2), Sm-N (2), Sm-N (2), Sm-N (2), P-C.576(3), C-O.28(4), P2-C2.563(4), C2-O2.234(4); O-Sm-O2 7.64(9), O-Sm-O (8), O2-Sm-O (8), O-Sm-N 89.49(8), N-Sm-N (7), N4-Sm- N3 54.7(7), O2-Sm -N (8), O-Sm-N 89.49(8). S.I. 5

16 Figure S9: Molecular structure of [(DippForm)Sm(2,2,2-crypt)][DippForm] (8) in the solid state. The thermal ellipsoids are set at a 5% probability level.hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Sm-N 2.79(3), Sm-N (3), Sm-N 2.952(3), Sm-N2 2.97(2), N3-C26.36(4), N4-C26.36(5); N-Sm-N2 49.9(7), N-Sm-N (8), N3-C26-N4 29.9(3). Figure S: Molecular structure of [(2,2,2-crypt)Sm(OCP) 2 ] (9) in the solid state. The thermal ellipsoids are set at a 5% probability level. Hydrogen atoms and solvent molecules are omitted for clarity. Selected bond lengths [Å] and angles [ ]: Sm-O 2.568(6), Sm-O2 2.63(6), P-C.58(8), C-O.22(), P2-C2.59(9), C2-O2.25(), Sm-N 2.972(6), Sm-N2 2.99(7); O-Sm-O2 34.3(2), O-C-P 78.8(7), C-O-Sm 45.(5), O2-C2-P2 79.2(8), C2- O2-Sm 4.6(6). S.I. 6

17 Table S: Crystallographic table. Identification code B 8 9 CCDC Empirical formula C55H78N4O2PY C55H78N4NdO2P C8H28N4NaO.5P2Y C8H28N4NaNdO.5P2 C8H46N8Nd2O2P2 C66H2N4O7Sm C38H59N2O7PSm C8.7H28.N4NaO.65P2Sm C68H6N6O6Sm C2H36N2O8P2Sm Formula weight Temperature/K 5(2) 293(2) 5(2) 5(2) 5(2) 5(2) 5(2) 5(2) 5(2) 5(2) Crystal system triclinic triclinic monoclinic monoclinic triclinic orthorhombic monoclinic monoclinic orthorhombic monoclinic Space group P- P- P2/n P2/n P- P222 P2/n P2/n P222 Pc a/å 2.394(5) 6.299(3) 6.647(2) 6.647(2) 2.339(3).6().5(2) 6.674(3).36(2).237(2) b/å (6) (3) 24.65(3) 24.65(3) 3.458(3) 2.77(2) (6) 24.6(5) 2.34(4) (9) c/å 5.93(6) (8) 2.649(2) 2.649(2) 6.372(3) (3) 3.27(3) 2.762(4) 28.94(6) (5) α/ (3) 8.844(2) (3) β/ 9.95(3) 83.34(2) 93.97() 93.97() 89.92(3) 9 95.(3) 92.84(3) (3) γ/ 97.9(3) (2) (3) Volume/Å (9) (3) 844.2(7) 844.2(7) () () 4.5(4) 859(3) 6552(2) (9) Z ρcalcg/cm 3,83,252,93,236,266,252,353,23,27,67 μ/mm 2,42 8,47,837 5,557 8,383 7,258,464 6,4 7,45 8,73 F() Crystal size/mm Radiation CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) CuKα (λ =.5484) 2Θ range for data collection/ to to to to to to to to to to Index ranges -5 h, -7 k 7, - 9 l 2-6 h 2, -2 k 2, - 36 l 37-8 h 2, -3 k 25, - 2 l 25-2 h 2, -29 k 3, - 26 l 26 - h 5, -6 k 6, - 2 l 2-3 h 2, -6 k 25, - 34 l 35 - h 3, -3 k 34, - 6 l 6-9 h 2, -3 k 3, - 2 l 25-3 h 2, -26 k 26, - 34 l 35-4 h 4, -2 k, - 3 l 29 Reflections collected Independent reflections 988 [Rint =.269, Rsigma =.258] [Rint =.345, Rsigma =.48] 7464 [Rint =.326, Rsigma =.286] 76 [Rint =.3, Rsigma =.287] 5 [Rint =.67, Rsigma =.758] 337 [Rint =.5, Rsigma =.52] 85 [Rint =.457, Rsigma =.52] 7563 [Rint =.442, Rsigma =.485] 363 [Rint =.57, Rsigma =.34] 989 [Rint =.44, Rsigma =.436] Data/restraints/parameters 988// // /9/97 76/9/97 5// /3/74 85// /9/ /48/ /2/597 Goodness-of-fit on F 2,4,52,8,39,56,39,5,34,2,25 Final R indexes [I>=2σ (I)] R =.322, wr2 =.82 R =.439, wr2 =.66 R =.444, wr2 =.27 R =.38, wr2 =.78 R =.44, wr2 =.987 R =.48, wr2 =.999 R =.373, wr2 =.898 R =.369, wr2 =.888 R =.248, wr2 =.586 R =.49, wr2 =.28 Final R indexes [all data] R =.335, wr2 =.83 R =.6, wr2 =.286 R =.58, wr2 =.69 R =.356, wr2 =.88 R =.59, wr2 =.66 R =.477, wr2 =.47 R =.444, wr2 =.953 R =.496, wr2 =.987 R =.26, wr2 =.593 R =.45, wr2 =.39 Largest diff. peak/hole / e Å -3.54/ /-.3.83/-.45.6/-.65./-.8.96/-.72.7/ / / /-.4 Flack parameter none none none none none -.33(3) none none -.28(2).7(4) S.I. 7

18 V. NMR Spectra D (d) C (t) 6.64 A (d) * * Figure S: H NMR spectrum of [K(DippForm)] in thf-d 8. Asterixes denote thf (solvent) peaks * 9 8 * Figure S2: 3 C{ H} NMR spectrum of [K(DippForm)] in thf-d 8. Asterixes denote residual thf (solvent) peaks. S.I. 8

19 B (d) 8.7 A (d) Figure S3: H NMR spectrum of [(DippForm) 2 YCl(thf)] (A) in C 6 D A (d) Figure S4: 3 C{ H} NMR spectrum of [(DippForm) 2 YCl(thf)] (A) in C 6 D 6. S.I. 9

20 Figure S5: H-{ 89 Y} HMQC NMR spectrum (C 6 D 6 ) of [(DippForm) 2 YCl(thf)] (A) in C 6 D 6. The 89 Y NMR spectrum is on the vertical axis and the H NMR spectrum is on the horizontal axis Figure S6: 89 Y{ H} INEPT NMR spectrum (C 6 D 6 ) of [(DippForm) 2 YCl(thf)] (A) in C 6 D 6. S.I. 2

21 Figure S7: H NMR spectrum of [(DippForm) 2 NdCl(thf)] (B) in C 6 D Figure S8: H NMR spectrum of [(DippForm) 2 Y(OCP)(thf)] () in C 6 D 6. The NMR solvent resonance is marked with *. S.I. 2

22 Figure S9: 3 C{ H} NMR spectrum of [(DippForm) 2 Y(OCP)(thf)] () in C 6 D 6. The NMR solvent resonance is marked with *. Figure S2: 3 P{ H} NMR spectrum of [(DippForm) 2 Y(OCP)(thf)] () in C 6 D 6. S.I. 22

23 Figure S2: H-{ 89 Y} HMQC NMR spectrum (C 6 D 6 ) of [(DippForm) 2 Y(OCP)(thf)] () in C 6 D 6. The 89 Y NMR spectrum is on the vertical axis and the H NMR spectrum is on the horizontal axis. Figure S22: 89 Y{ H} INEPT NMR spectrum of [(DippForm) 2 Y(OCP)(thf)] () in C 6 D 6. S.I. 23

24 Figure S23: H NMR spectrum of [(DippForm) 2 Nd(OCP)((thf)] (2) in C 6 D Figure S24: 3 P{ H} NMR spectrum of [(DippForm) 2 Nd(OCP)((thf)] (2) in C 6 D 6. S.I. 24

25 * * Figure S25: H NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in thf-d 8. The NMR solvent resonances are marked with * * 3 * Figure S26: 3 C{ H} NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in thfd 8. The NMR solvent resonances are marked with *. S.I. 25

26 Figure S27: 3 P{ H} NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in thfd 8. Figure S28: H-{ 89 Y} HMQC NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in thf-d 8. The 89 Y NMR spectrum is on the vertical axis and the H NMR spectrum is on the horizontal axis. S.I. 26

27 Figure S29: 89 Y{ H} INEPT NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in thf-d 8. Figure S3: Variable temperature H NMR spectra of [Na(8-crown- 6)(thf) 2 ][(DippForm) 2 Y(OCP) 2 (thf)] (3) in thf-d 8 in a range between 233 K and 333 K. S.I. 27

28 Figure S3: H NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Nd(OCP) 2 (thf)] (4) in thf-d Figure S32: 3 P{ H} NMR spectrum of [Na(8-crown-6)(thf) 2 ][(DippForm) 2 Nd(OCP) 2 (thf)] (4) in thf-d 8. S.I. 28

29 * 4 2 * Fi gure S33: H NMR spectrum of [(DippForm) 2 Nd(μ 2 -OCP)] 2 (5) in thf-d 8. * denote residual solvent peaks from thf-d Figure S34: 3 P{ H} NMR spectrum of [(DippForm) 2 Nd(μ 2 -OCP)] 2 (5) in thf-d 8. S.I. 29

30 Figure S35: H NMR spectrum of [(DippForm)Sm(8-crown-6)(thf)][DippForm] (6) in thf-d B (t) 6.29 A (d) Figure S36: H NMR spectrum of [(DippForm)Sm(OCP)(8-crown-6)] (7) in C 6 D 6. S.I. 3

31 Figure S37: 3 C{ H} NMR spectrum of [(DippForm)Sm(OCP)(8-crown-6)] (7) in C 6 D Figure S38: 35dept NMR spectrum of [(DippForm)Sm(OCP)(8-crown-6)] (7) in C 6 D 6. S.I. 3

32 Figure S39: 3 P{ H} NMR spectrum of [(DippForm)Sm(OCP)(8-crown-6)] (7) in C 6 D Figure S4: H NMR spectrum of [(DippForm)Sm(2,2,2-crypt)][DippForm] (8) in pyridine-d 5. S.I. 32

33 * * * Figure S4: H NMR spectrum of [(2,2,2-crypt)Sm(OCP) 2 ] (9) in pyridine-d 5. * denote residual solvent peaks from pyridine-d * * * Figure S42: 3 C{ H} NMR spectrum of [(2,2,2-crypt)Sm(OCP) 2 ] (9) in pyridine-d 5. * denote residual solvent peaks from pyridine-d 5. S.I. 33

34 Figure S43: 3 P{ H} NMR spectrum of [(2,2,2-crypt)Sm(OCP) 2 ] (9) in pyridine-d 5. S.I. 34

35 References []D. Heift, Z. Benko, H. Grützmacher, Dalton Trans. 24, 43, [2]A. G. Massey, A. J. Park, J. Organomet. Chem. 964, 2, [3]K. Hirano, S. Urban, C. Wang, F. Glorius, Org. Lett. 29,, [4]P. L. Watson, T. H. Tulip, I. Williams, Organometallics 99, 9, [5]C. Schoo, S. Bestgen, M. Schmidt, S. N. Konchenko, M. Scheer, P. W. Roesky, Chem. Commun. 26, 52, [6]G. B. Deacon, P. C. Junk, J. Wang, D. Werner, Inorg. Chem. 24, 53, [7]M. L. Cole, P. C. Junk, J. Organomet. Chem. 23, 666, [8]J. Cosier, A. M. Glazer, J. Appl. Crystallogr. 986, 9, 5-7. [9]CrysAlisPro, Agilent Technologies, Version [] G. M. Sheldrick, 23, SHELXS-23. [] C. B. Hubschle, G. M. Sheldrick, B. Dittrich, J. Appl. Crystallogr. 2, 44, S.I. 35