Publications
86. Wee, M. Y.-S.; Quek, S.; Wu, C.-S.; Su, M.-D.; So, C.-W. Isolable Spirocyclic Silylone: π-Delocalized Spiro[3.3]heptasila-2,6-diylidone. J. Am. Chem. Soc. 2024, 146, 14410-14415.
85. Siwatch, R. K.; Yang, M.-C.; Su, M.-D.; So, C.-W. A Digermanium(III) 1,2-Dication Stabilized by Amidinate and cAAC-Phosphinidenide Ligands. Inorg. Chem. 2024, 63, 8511−8515.
84. Fan, J.; Koh, A.-P.; Wu, C.-S.; Su, M.-D.; So, C.-W. Carbon dioxide capture and functionalization by bis(N-heterocyclic carbene)-borylene complexes. Nat Commun. 2024, 15, 3052.
83. Teo, Y.-C.; Loh, D.; Leong, B.-X.; Zhang, Z.-F.; Su, M.-D.; So, C.-W. NHC-Silyliumylidene Cation-Catalyzed Hydroboration of Isocyanates with Pinacolborane. Inorg. Chem. 2023, 62, 16867−16873.
82. Fan, J.; Koh, A.-P.; Zhou, J.; Zhang, Z.-F.; Wu, C.-S.; Webster, R. D.; Su, M.-D.; So, C.-W. Tetrakis(N-heterocyclic Carbene)-Diboron(0): Double Single-Electron-Transfer Reactivity. J. Am. Chem. Soc. 2023, 145, 11669−11677.
81. Zhang, S.-H.; Tang, A. S. Y.; Chin, R. S. L.; Goh, J. Y.; Ong, M. C.; Lim, W. J. L.; Yap, A. T. W.; So, C.-W. Stability studies of ALD-52 and its homologue 1P-LSD. J Forensic Sci. 2023, 68, 1009–1019.
80. Fan, J.; Yang, M.-C.; Su, M.-D.; So, C.-W. N-Phosphinoamidinato Silylene– and Phosphine–Borylborylene Complexes. Inorg. Chem. 2023, 62, 863–870.
79. Fan, J.; Chia, P.-T.; Zhang, Z.-F.; Yang, M.-C.; Su, M.-D.; So, C.-W. A Pyridine-Stabilized N-Phosphinoamidinato N-Heterocyclic Carbene-Diboravinyl Cation: Boron Analogue of Vinyl Cation. Angew. Chem.Int. Ed. 2022, 61, e202212842.
78. Lee, J.; Fan, J.; Koh, A.-P.; Cheang, W.-J.J; Yang, M.-C.; Su, M.-D.; So, C.-W. Amidinato Isopropylmethylamidosilylene-Catalyzed Hydroboration of Carbonyl Compounds. Eur. J. Inorg.Chem. 2022, e202200129.
77. Chia, C.-C.; Li, Y. ; Xiao, L.; Yang, M.-C.; Su, M.-D.; So, C.-W. Lewis Pair Polymerization of Alkyl Methacrylate by Amidinato Silicon Compounds and Tris(pentafluorophenyl)borane. Eur. J. Org. Chem. 2022, e202200003.
76. Fan, J.; Quek, S.; Yang, M.-C.; Zhang, Z.-F.; Su, M.-D.; So, C.-W. Reversible CO2 activation by a N-phosphinoamidinato digermyne. Chem. Commun. 2022, 58, 1033-1036.
75. Fan, J.; Yang, M.-C.; Su, M.-D.; So, C.-W. Amidinatoamidosilylene-Dibromodiborene. Inorg. Chem. 2021, 60, 16065–16069.
74. Fan, J.; Yang, M.-C.; Hooper J. N. T.; Su, M.-D.; So, C.-W. Diboron-Carbene Complexes Derived from a Geminal Dianion. Organometallics. 2021, 40, 1848-1853.
73. Zhu K. K.; Dutta S.; Han W. C.; Wang C. F.; Lee J.; Tan G. W.; Koley D.; So C.-W.; Li Y. Si(II) Cation-Promoted Formation of an Abnormal NHC-Bound Silylene and a cAAC-Silanyl Radical Ion. Inorg. Chem. 2021, 60, 7143-7149
72. Chia, C.-C.; Teo, Y.-C.; Cham, N.; Ho, S. Y.-F.; Ng, Z.-H.; Toh, H.-M.; Mezailles, N.; So, C.-W. Aluminum-Hydride-Catalyzed Hydroboration of Carbon Dioxide. Inorg. Chem. 2021, 60, 4569-4577
71. Fan, J.; Mah, J.-Q.; Yang, M.-C.; Su, M.-D.; So, C.-W. A N-Phosphinoamidinato NHC-Diborene Catalyst for Hydroboration. J. Am. Chem. Soc. 2021, 143, 1651-1660.
70. Leong, B.-X.; Teo, Y.-C.; Condamines, C.; Yang, M.-C.; Su, M.-D.; So, C.-W. A NHC-Silyliumylidene Cation for Catalytic N-Formylation of Amines Using Carbon Dioxide. ACS Catal. 2020, 10, 14824-14833.
69. Bin Ismail, M. L.; Ong, M. X.-Y.; So, C.-W. A Base-Stabilized Germylenyl Silaneditelluroate and 1,3-Diaza-2-silaallylgermylene. Eur. J. Inorg. Chem. 2020, 38, 3703-3707.
68. Khoo, S.; Siu, C.-K.; So, C.-W. A Base-Stabilized Silylene-Promoted C(sp3)-H Borylation and H2 Bond Activation. Inorg. Chem. 2020, 59, 9551-9559.
67. Leong, B.-X.; Lee, J.; Li, Y.; Yang, M.-C.; Siu, C.-K.; Su, M.-D.; So, C.-W. A Versatile NHC-Parent Silyliumylidene Cation for Catalytic Chemo- and Regioselective Hydroboration. J. Am. Chem. Soc. 2019, 141, 17629-17636
66. Bin Ismail, M. L.; So, C.-W. Synthesis of a Dimeric Phosphine-Stabilized Phosphidogermanium(I)-Amidogermanium(II) Derivative. Chem. Commun. 2019, 55, 2074-2077.
65. Khoo, S.; Cao, J.; Yang, M.-C.; Shan, Y.-L.; Su, M.-D.; So, C.-W. Synthesis of a Dimeric Base-Stabilized Cobaltosilylene Complex for Catalytic C-H Bond Functionalization and C-C Bond Formation. Chem. - Eur. J. 2018, 24, 14329-14334
64. Khoo, S.; Cao, J.; Ng, F.; So, C.-W. Synthesis of a Base-Stabilized Silicon(I)-Iron(II) Complex for Hydroboration of Carbonyl Compounds. Inorg. Chem. 2018, 57, 12452-12455.
63. Khoo, S.; Shan, Y.-L.; Yang, M.-C.; Li, Y.; Su, M.-D.; So, C.-W. B-H Bond Activation by an Amidinate-Stabilized Amidosilylene: Non-Innocent Amidinate Ligand. Inorg. Chem. 2018, 57, 5879-5887.
62. Seow, C.; Bin Ismail, M. L.; Xi, H.-W.; Li, Y.; Lim, K. H.; So, C.-W. A Bis(germyliumylidene)silver(I) Complex Dication. Organometallics. 2018, 37, 1368-1372.
61. Chan, Y.-C.; Leong, B.-X.; Li, Y.; Yang, M.-C.; Li, Y.; Su, M.-D.; So, C.-W. A Dimeric NHC-Silicon Monotelluride: Synthesis, Isomerization and Reactivity. Angew. Chem. Int. Ed. 2017, 56, 11565-11569.
60. Li, Y.; Chan Y.-C.; Leong, B.-X.; Li, Y.; Richards, E.; Purushothaman, I.; De, S.; Parameswaran, P.; So, C.-W. Trapping of a Silicon(I) Radical by Carbenes: Synthesis of a Cationic cAAC-Stabilized Silicon(I) Radical and NHC-Stabilized Parent Silyliumylidene Cation. Angew. Chem. Int. Ed. 2017, 56, 7573-7578.
59. Ismail, M. L. B.; Liu, F.-Q.; Yim, W.-L.; Ganguly, R.; Li, Y.; So, C.-W. Reactivity of a Base-Stabilized Germanium(I) Dimer toward Group 9 Metal(I) Chloride and Dimanganese Decacarbonyl. Inorg. Chem. 2017, 56, 5402-5410.
58. Li, Y.; Siwatch, R. K.; Mondal, T.; Li, Y.; Ganguly, R.; Koley, D.; So, C.-W. Diverse Bonding Activations in the Reactivity of a Pentaphenylborole toward Sodium Phosphaethynolate: Heterocycle Synthesis and Mechanistic Studies. Inorg. Chem. 2017, 56, 4112-4120.
57. Shan, Y.-L.; Leong, B.-X.; Xi, H.-W.; Ganguly, R.; Li, Y.; Lim, K. H.; So, C.-W. Reactivity of an Amidinato Silylene and Germylene toward Germanium(II), Tin(II) and Lead(II) Halides. Dalton Trans. 2017, 46, 3642-3648.
56. Shan, Y.-L.; Leong, B.-X.; Li, Y.; Ganguly, R.; So, C.-W. Donor-Acceptor Stabilized Tetra(silanimine). Inorg. Chem. 2017, 56, 1609-1615.
55. Zhang, S.-H.; Carter, E.; Xi, H.-W.; Li, Y.; Lim, K. H.; So, C.-W. Delocalized Hypervalent Silyl Radical Supported by Amidinate and Imino Substituents. Inorg. Chem. 2017, 56, 701-704.
54. Li, Y.; Chan, Y.-C.; Li, Y.; Purushothaman, I.; De, S.; Parameswaran, P.; So, C.-W. Synthesis of a Bent 2-Silaallene with a Perturbed Electronic Structure from a Cyclic Alkyl(amino) Carbene-Diiodosilylene. Inorg. Chem. 2016, 55, 9091-9098.
53. Leung, W.-P.; Chan, Y.-C.; So, C.-W.; Mak, T. C. W., Reactivity Study of a Pyridyl-1-azaallylgermanium(I) Dimer: Synthesis of Heavier Ether and Ester Analogues of Germanium. Inorg. Chem. 2016, 55, 3553.-3557.
52. Seow, C.; Li, Y.; So, C.-W. Synthesis of a Germylidenide Anion from the C-C Bond Activation of a Bis(Germylene). Organometallics. 2016, 35, 1060-1063.
51. Seow, C.; Yim, W.-L.; Li, Y.; Ganguly, R.; So, C.-W. Synthesis of an N-heterocyclic Carbene-Stabilized Siladiimide. Inorg. Chem. 2016, 55, 4-6.
50. Khoo, S.; Yeong, H.-X.; Li, Y.; Ganguly, R.; So, C.-W. Amidinate-Stabilized Group 9 Metal-Silicon(I) Dimer and –Silylene Complexes. Inorg. Chem. 2015, 54, 9968-9975.
49. Chan, Y.-C.; Li, Y.; Ganguly, R.; So, C.-W. Acyclic Amido-containing Silanechalcogenones. Eur. J. Inorg. Chem. 2015, 23, 3792.
48. Yang, Y.-X.; Li, Y.; Ganguly, R.; So, C.-W. Instability of Metal 1,3-Benzodi(thiophosphinoyl)methandiide Complexes: Formation of Hafnium, Tin and Zirconium Complexes of 1,3-Benzodi(thiophosphinoyl)thioketone Dianionic Ligand [1,3-C6H4(PhPS)2CS]2. Dalton Trans. 2015, 44, 12633-12639.
47. Leung, W.-P.; Chan, Y.-C.; So, C.-W. Chemistry of Heavier Group 14 Base-Stabilized Heterovinylidenes. Organometallics. 2015, 34, 2067-2085.
46. Guo, J.-Y.; Chan, Y.-C.; Li, Y.; Ganguly, R.; So, C.-W. Oxo-Bridged Bis(Group 4 Metal Unsymmetric Phosphonium-Stabilized Carbene) Complexes. Organometallics. 2015, 34, 1238-1244.
45. Ho, S. Y. F.; So, C.-W.; Saffon-Merceron, N.; Mezailles, N. Formation of a Zwitterionic Boronium Species from the Reaction of a Stable Carbenoid with Borane: CO2 Reduction. Chem. Commun. 2015, 51, 2107-2110.
44. Shan, Y.-L.; Yim, W.-L.; So, C.-W. A N-heterocyclic Silylene Stabilized Digermanium(0) Complex. Angew. Chem. Int. Ed. 2014, 53, 13155-13158.
43. Chia, S.-P.; Carter, E.; Xi, H.-W.; Li, Y.; So, C.-W. Group II Metal Complexes of Germylidendiide Dianion Radical and Germylidenide Anion. Angew. Chem. Int. Ed. 2014, 53, 8455-8458.
42. Yeong, H.-X.; Li, Y.; So, C.-W. A Base-Stabilized Silyliumylidene Cation as a Ligand for Rhodium and Tungsten Complexes. Organometallics. 2014, 33, 3646-3648.
41. Chia, S.-P.; Li, Y.; Ganguly, R.; So, C.-W. Heteroleptic Germanium(II) and Tin(II) Chlorides Supported by Anionic Ligands Derived from 2,3-Dimethyl-1,4-diaza-1,3-butadiene. Eur. J. Inorg. Chem. 2014, 526-532.
40. Zhang, S.-H.; Xi, H.-W.; Lim, K. H.; So, C.-W. An Extensive s-, p- and n-Electron Delocalized Si4 Ring. Angew. Chem. Int. Ed. 2013, 52, 12364-12367.
39. Yeong, H.-X.; Xi, H.-W.; Li, Y.; Kunnappilly, S. B.; Chen, B.; Lau, K.-C.; Hirao, H.; So, C.-W. Zwitterionic Base-Stabilized Digermadistannacyclobutadiene and Tetragermacyclobutadiene. Chem. Eur. J. 2013, 19, 14726-14731.
38. Chia, S.-P.; Li, Y.; So, C.-W. Synthesis and Characterization of a 2,6-Diiminophenylgermanium(II) Hydroxide, Azide, and Triazaphospole. Organometallics. 2013, 32, 5231-5234.
37. Yeong, H.-X.; Xi, H.-W.; Li, Y.; Lim, K. H.; So, C.-W. A Silyliumylidene Cation Stabilized by an Amidinate Ligand and 4-Dimethylaminopyridine. Chem. Eur. J. 2013, 19, 11786-11790
36. Heuclin, H.; Ho, S. Y.-F.; Le Goff, X. F.; So, C.-W.; Mézailles, N. Facile B-H Bond Activation of Borane by Stable Carbenoid Species. J. Am. Chem. Soc. 2013, 135, 8774-8777.
35. Chia, S.-P.; Xi, H. W.; Li, Y.; Lim, K. H.; So, C.-W. A Base-Stabilized Lead(I) Dimer and an Aromatic Plumbylidenide Anion. Angew. Chem. Int. Ed. 2013, 52, 6298-6301.
34. Yang, Y.-F.; Ganguly, R.; Li, Y.; So, C.-W. Reactivity of a Tin(II) 1,3-Benzodi(thiophosphinoyl)methanediide Complex toward Gallium, Germanium and Zinc Compounds. Organometallics. 2013, 32, 2643-2648.
33. Yang, Y.-F.; Foo, C.; Xi, H.-W.; Li, Y.; Lim, K. H.; So, C.-W. A Base-Stabilized 2-Silaallene. Organometallics. 2013, 32, 2267-2270.
32. Heuclin, H.; Fustier-Boutignon, M.; Ho, S. Y.-F.; Le Goff, X.-F.; Carenco, S.; So, C.-W.; Mézailles, N. Synthesis of Phosphorus(V)-Stabilized Geminal Dianions. The Cases of Mixed P═X/P→BH3 (X = S, O) and P═S/SiMe3 Derivatives. Organometallics. 2013, 32, 498-508.
31. Yang, Y.-F.; Foo, C.; Ganguly, R.; Li, Y.; So, C.-W. Synthesis of a Tin(II) 1,3-Benzobis(thiophosphinoyl)methanediide Complex and its Reactions with Aluminum Compounds. Organometallics. 2012, 31, 6538-6546.
30. Chia, S.-P.; Ganguly, R.; Li, Y.; So, C.-W. Reactivity of a Distannylene toward Potassium Graphite: Synthesis of a Stannylidenide Anion. Organometallics. 2012, 31, 6415-6419.
29. Guo, J.-Y.; Li, Y.; Ganguly, R.; So, C.-W. Reactivity of a Tin(II) (Iminophosphinoyl)(thiophosphinoyl)methanediide Complex toward Isocyanates and Rhodium(I) Chloride. Organometallics. 2012, 31, 3888-3893.
28. Guo, J.-Y.; Xi, H.-W.; Nowik, I.; Herber, R. H.; Li, Y.; Lim, K. H.; So, C.-W. Reactivity of a Tin(II) (Iminophosphinoyl)(thiophosphinoyl)methanediide Complex Toward Sulfur: Synthesis and 119Sn Mössbauer Spectroscopic Studies of [{(μ-S)SnC(PPh2=NSiMe3)(PPh2=S)}3Sn(μ3-S)]. Inorg. Chem. 2012, 51, 3996-4001.
27. Yeong, H.-X.; Zhang, S.-H.; Xi, H.-W.; Guo, J.-D.; Lim, K. H.; Nagase, S.; So, C.-W. An Amidinate-Stabilized Germatrisilacyclobutadiene Yilde. Chem. Eur. J. 2012, 18, 2685-2691.
26. Zhang, S.-H.; Xi, H.-W.; Lim, K. H.; Meng, Q.; Huang, M.-B.; So, C.-W. Synthesis and Characterization of a Singlet Delocalized 2,4-Diimino-1,3-disilacyclobutanediyl and a Silylenylsilaimine. Chem. Eur. J. 2012, 18, 4258-4263.
25. Chia, S.-P.; Yeong, H.-X.; So, C.-W. Reactivity of Digermylenes toward Potassium Graphite: Synthesis and Characterization of Germylidenide Anions. Inorg. Chem. 2012, 51, 1002-1010.
24. Zhang, S.-H.; So, C.-W. Synthesis and Characterization of an Amidinate-stabilized Bisgermylene Oxide and Sulfide. Organometallics. 2011, 30, 2059-2062.
23. Zhang, S.-H.; Xi, H.-W.; Lim, K. H.; So, C.-W. Synthesis and Characterization of an Amidinate-Stabilized Siladithiocarboxylate and Its Germanium(II) Complex. Organometallics. 2011, 30, 3686-3689.
22. Zhang, S.-H.; Yeong, H.-X.; So, C. W. Reactivity of a Silylsilylene Bearing a Functionalized Diaminochlorosilyl Substituent. Chem. Eur. J. 2011, 17, 3490-3499.
21. Yeong, H.-X.; Xi, H.-W.; Lim, K. H.; So, C.-W. Synthesis and Characterization of an Amidinate-stabilized cis-1,2-Disilylenylethene [cis-LSi{C(Ph)=C(H)}SiL] (L = PhC(NtBu)2) and a Singlet Delocalized Biradicaloid [LSi(μ2-C2Ph2)2SiL]. Chem. Eur. J. 2010, 16, 12956-12961.
20. Zhang, S.-H.; Yeong, H.-X.; Xi, H.-W.; Lim, K. H.; So, C.-W. Hydrosilylation of a Silicon(II) Hydride: Synthesis and Characterization of a Remarkable Silylsilylene. Chem. Eur. J. 2010, 16, 10250-10254.
19. Guo, J.; Lau, K.-C.; Xi, H.-W.; Lim, K. H.; So, C.-W. Synthesis and Characterization of a Tin(II) Bis(phosphinoyl)methanediide Complex: a Stannavinylidene Derivative. Chem. Commun. 2010, 49, 1929-1931.
18. Guo, J.; Lee, J.-S.; Foo, M.-C.; Lau, K.-C.; Xi, H.-W.; Lim, K. H.; So, C.-W. Synthesis and Characterization of Magnesium and Aluminum Bis(phosphoranyl)methanediide Complexes. Organometallics. 2010, 29, 939-944.
17. Yeong, H.-X.; Lau, K.-C.; Xi, H.-W.; Lim, K. H.; So, C.-W. Reactivity of a Disilylene [{PhC(NBut)2}Si]2 toward Bromine: Synthesis and Characterization of a Stable Monomeric Bromosilylene. Inorg. Chem. 2010, 49, 371-373.
16. Foo, C.; Lau, K.-C.; Yang, Y.-F.; So, C.-W. Synthesis and Characterization of a Germanium Bismethanediide Complex. Chem. Commun. 2009, 6816-6818.
15. Chen, J.-H.; Guo, J.; Li, Y.; So, C.-W. Synthesis and Structure of [Li2C(PPh2=NSiMe3)(PPh2=S)]: a Geminal Dianionic Ligand. Organometallics. 2009, 28, 4617-4620.
14. So, C.-W.; Watanabe, D.; Wakamiya, A.; Yamaguchi, S. Synthesis and Structural Characterization of Pentaarylboroles and Their Dianions. Organometallics. 2008, 27, 3496-3501.
13. So, C.-W.; Roesky, H. W.; Gurubasavaraj, P. M.; Oswald, R. B.; Gamer, M. T.; Jones, P. G.; Blaurock, S. Synthesis and Structures of Heteroleptic Silylenes. J. Am. Chem. Soc. 2007, 129, 12049-12054.
12. So, C.-W.; Roesky, H. W.; Oswald, R. B.; Pal, A.; Jones, P. G. Synthesis and Characterization of [{PhC(NBut)2}Si(S)SBut]: a Silicon Thioester Analogue with the Si(=S)-S-Skeleton. Dalton Trans. 2007, 5241-5244.
11. Yang, Y.; Roesky, H. W.; Jones, P. G.; So, C.-W.; Zhang, Z.; Herbst-Irmer, R.; Ye, H. Synthesis and Structural Characterization of Monomeric Heterobimetallic Oxides with a Ge(II)-O-M Skeleton (M = Yb, Y). Inorg. Chem. 2007, 46, 10860-10863.
10. Leung, W.-P.; Kan, K.-W.; So, C.-W.; Mak, T. C. W. Formation of Germenes from Bis(germavinylidene). Organometallics. 2007, 26, 3802-3806.
9. Leung, W.-P.; Kan, K.-W.; So, C.-W.; Mak, T. C. W. Some Addition Reactions of Bisgermavinylidene. Appl. Organometal. Chem. 2007, 21, 814-818.
8. So, C.-W.; Roesky, H. W.; Magull, J.; Oswald, R. B. Synthesis and Characterization of [PhC(NtBu)2]SiCl: a Stable Monomeric Chlorosilylene. Angew. Chem. Int. Ed. 2006, 45, 3948-3950.
7. Leung, W.-P.; So, C.-W.; Chong, K.-H.; Kan, K.-W.; Chan, H.-S.; Mak, T. C. W. Reactivity of Pyridyl-1-azaallyl Germanium(II) Chloride: Synthesis of Novel Lithium Germinate [{(PhCC)3Ge}3GeLi(Et2O)3] and Ge(II)-M(I) (M = Cu and Au) Adducts. Organometallics. 2006, 25, 2851-2858.
6. Leung, W.-P.; Chong, K.-H.; Wu, Y.-S.; So, C.-W.; Chan, H.-S.; Mak, T. C. W. Synthesis of Chalcogeno[3-(pyrid-2-yl)-1-azaallyl]germanium Complexes. Eur. J. Inorg. Chem. 2006, 808-812.
5. Leung, W.-P.; So, C.-W.; Wu, Y.-S.; Li, H.-W.; Mak, T. C. W. Synthesis of Group 14 Metal Enamido, Alkenyl, Imido and Alkenyl-Amido Complexes from a Monoanionic Pyridyl-1-azaallyl Ligand. Eur. J. Inorg. Chem. 2005, 513-521.
4. Leung, W.-P.; So, C.-W.; Kan, K.-W.; Chan, H.-S.; Mak, T. C. W. Synthesis of a Manganese Germavinylidene Complex from Bis(germavinylidene). Inorg. Chem. 2005, 44, 7286-7288.
3. Leung, W.-P.; So, C.-W.; Kan, K.-W.; Chan, H.-S.; Mak, T. C. W. Synthesis of Novel Metal-Germavinylidene Complexes from Bisgermavinylidene. Organometallics. 2005, 24, 5033-5037.
2. Leung, W.-P.; So, C.-W.; Wang, Z.-X.; Wang, J.-Z.; Mak, T. C. W. Synthesis of Bisgermavinylidene and Its Reaction with Chalcogens. Organometallics. 2003, 22, 4305-4311.
1. Leung, W.-P.; So, C.-W.; Wang, J.-Z.; Mak, T. C. W. A Novel Synthesis of Metallogermacyclopropane and Molybdenum Bis(iminophosphorano)carbene Complexes from Bisgermavinylidene. Chem. Commun. 2003, 248-249.