本篇論文主要為二配位零價過渡金屬錯合物的合成探討，以Cyclic alkyl amino carbine (CAAC)當作配位基，合成過渡金屬錯合物再進行還原反應測試，使用的金屬有V、Cr、Mo以早期過渡金屬為主。成功合成出的過渡金屬錯合物有錯合物6 VCl3(CAAC)、7 VCl3(CAAC)2、8 CrCl2(CAAC)2、9 CrCl(CAAC)、10 MoCl3(CAAC)2，依序是V、Cr、Mo的錯合物，將錯合物6、 7 、8 、9 、10進行還原反應。
嘗試使用的還原劑分別有鹼金族的Na、K，鹼土族以Mg來進行，帶有hydride的NaH、KH以及Superhydride solution。
成功還原出的例子有錯合物15、16，以及得到金屬簇合物14，經由單晶X光繞射儀鑑定結構，發現在錯合物15、16結構中的CAAC有特別的配位狀態，與一般以CAAC的Carbene上的C鍵結狀態在鍵長上有明顯差異，在過往的文獻中並沒有看到此現象。

Low coordinate zero valent transition metal complex are our goal in this research. We use the nova Cyclic alkyl amino carbene as ligand to synthesis transition metal complex. These complex which center metal are early transition metal. After that, we try reducing agent such as Na, K, Mg to achieve zero valent low coordinate transition metal complex. Eventually, complex 15,16 are successful reduction in superhydride solution. Single crystal X-ray diffraction studies show that the ligand bonded in different ways, had never seen before.

(1) Iii, A. J. A.; Harlow, R. L.; Kline, M. A Stable Crystalline Carbene. J.Am.Chem.Soc. 1991, 113, 361–363.
(2) Huang, J.; Schanz, H.-J.; Stevens, E. D.; Nolan, S. P. Influence of Sterically Demanding Carbene Ligation on Catalytic Behavior and Thermal Stability of Ruthenium Olefin Metathesis Catalysts. Oranometallics 1999, No. 18, 5375–5380.
(3) Ahmed, M.; Arnauld, T.; Barrett, A. G. M.; Braddock, D. C.; Flack, K.; Procopiou, P. A. Allene Cross-Metathesis: Synthesis of 1,3-Disubstituted Allenes. Org.Lett 2000, 2 (4), 551–553.
(4) Jafarpour, L.; Heck, M.-P.; Baylon, C.; Lee, H. M.; Mioskowski, C.; Nolan, S. P. Preparation and Activity of Recyclable Polymer-Supported Ruthenium Olefin Metathesis Catalysts. Oranometallics. 2002, 21 (4), 671–679.
(5) Schwarz, J.; Böhm, V. P. W.; Gardiner, M. G.; Grosche, M.; Herrmann, W. A.; Hieringer, W.; Raudaschl-Sieber, G. Polymer-Supported Carbene Complexes of Palladium: Well-Defined, Air-Stable, Recyclable Catalysts for the Heck Reaction. Chem. – Eur. J. 2000, 6 (10), 1773–1780.
(6) Muehlhofer, M.; Strassner, T.; Herrmann, W. A. New Catalyst Systems for the Catalytic Conversion of Methane into Methanol. Angew. Chem. Int. Ed. 2002, 41 (10), 1745–1747.
(7) Nguyen, T.; Sutton, A. D.; Brynda, M.; Fettinger, J. C.; Long, G. J.; Power, P. P. Synthesis of a Stable Compound with Fivefold Bonding Between Two Chromium(I) Centers. Science 2005, 310 (5749), 844–847.
(8) Ni, C.; Fettinger, J. C.; Long, G. J.; Power, P. P. Terphenyl Substituted Derivatives of Manganese(Ii): Distorted Geometries and Resistance to Elimination. Dalton Trans. 2010, 39 (44), 10664.
(9) Ni, C.; Power, P. P. Insertion Reactions of a Two-Coordinate Iron Diaryl with Dioxygen and Carbon Monoxide. Chem. Commun. 2009, No. 37, 5543.
(10) Ni, C.; Stich, T. A.; Long, G. J.; Power, P. P. Unusual Magnetic Properties of a Two-Coordinate Heteroleptic Linear Cobalt(Ii) Complex. Chem. Commun. 2010, 46 (25), 4466.
(11) Wolf, R.; Ni, C.; Nguyen, T.; Brynda, M.; Long, G. J.; Sutton, A. D.; Fischer, R. C.; Fettinger, J. C.; Hellman, M.; Pu, L.; Power, P. P. Substituent Effects in Formally Quintuple-Bonded ArCrCrAr Compounds (Ar = Terphenyl) and Related Species. Inorg. Chem. 2007, 46 (26), 11277–11290.
(12) Kays (née Coombs), D. L.; Cowley, A. R. Monomeric, Two-Coordinate Mn, Fe and Co( II ) Complexes Featuring 2,6-(2,4,6-Trimethylphenyl)Phenyl Ligands. Chem Commun 2007, No. 10, 1053–1055.
(13) Buttrus, N. H.; Eaborn, C.; Hitchcock, P. B.; Smith, J. D.; Sullivan, A. C. Preparation and Crystal Structure of a Two-Co-Ordinate Manganese Compound, Bis[Tris(Trimethyl)Silylmethyllmanganese. J. Am. Chem. Soc. 1985, 2.
(14) LaPointe, A. M. Fe[C(SiMe3)3]2: Synthesis and Reactivity of a Monomeric Homoleptic Iron(II) Alkyl Complex. Inorganica Chim. Acta 2003, 345, 359–362.
(15) Chen, H.; Bartlett, R. A.; Olmstead, M. M.; Power, P. P.; Shoner, S. C. Series of Two-Coordinate and Quasi-Two-Coordinate Transition-Metal Complexes: Synthesis, Structural, and Spectroscopic Studies of Sterically Demanding Borylamide Ligands -NRBR’2 (R = Ph, R’ = Mes, Xyl; R = R’ = Mes), Their Lithium Salts, Li(Et2O)2NRBR’2, and Their Transition-Metal Derivatives, M(NPhBMes2)2 (M = Cr, Co, Ni), Co(NPhBXyl2)2 and M(NMesBMes2)2 (M = Cr .Fwdarw. Ni). J. Am. Chem. Soc. 1990, 112 (3), 1048–1055.
(16) Boynton, J. N.; Merrill, W. A.; Reiff, W. M.; Fettinger, J. C.; Power, P. P. Two-Coordinate, Quasi-Two-Coordinate, and Distorted Three Coordinate, T-Shaped Chromium(II) Amido Complexes: Unusual Effects of Coordination Geometry on the Lowering of Ground State Magnetic Moments. Inorg. Chem. 2012, 51 (5), 3212–3219.
(17) Ni, C.; Rekken, B.; Fettinger, J. C.; Long, G. J.; Power, P. P. Two-Coordinate, Homoleptic Manganese(Ii) Primary Terphenyl Amido Complexes: The Effects of Secondary Coordination on Geometry and Lewis Base Complexation. Dalton Trans. 2009, No. 39, 8349.
(18) Merrill, W. A.; Stich, T. A.; Brynda, M.; Yeagle, G. J.; Fettinger, J. C.; De Hont, R.; Reiff, W. M.; Schulz, C. E.; Britt, R. D.; Power, P. P. Direct Spectroscopic Observation of Large Quenching of First-Order Orbital Angular Momentum with Bending in Monomeric, Two-Coordinate Fe(II) Primary Amido Complexes and the Profound Magnetic Effects of the Absence of Jahn− and Renner−Teller Distortions in Rigorously Linear Coordination. J. Am. Chem. Soc. 2009, 131 (35), 12693–12702.
(19) Bryan, A. M.; Merrill, W. A.; Reiff, W. M.; Fettinger, J. C.; Power, P. P. Synthesis, Structural, and Magnetic Characterization of Linear and Bent Geometry Cobalt(II) and Nickel(II) Amido Complexes: Evidence of Very Large Spin–Orbit Coupling Effects in Rigorously Linear Coordinated Co 2+. Inorg. Chem. 2012, 51 (6), 3366–3373.
(20) Lin, C.-Y.; Fettinger, J. C.; Grandjean, F.; Long, G. J.; Power, P. P. Synthesis, Structure, and Magnetic and Electrochemical Properties of Quasi-Linear and Linear Iron(I), Cobalt(I), and Nickel(I) Amido Complexes. Inorg. Chem. 2014, 53 (17), 9400–9406.
(21) Weller, R.; Müller, I.; Duhayon, C.; Sabo-Etienne, S.; Bontemps, S.; Werncke, C. G. Quasilinear 3d-Metal( I ) Complexes [KM(N(Dipp)SiR 3 ) 2 ] (M = Cr–Co) – Structural Diversity, Solution State Behaviour and Reactivity. Dalton Trans. 2021, 50 (14), 4890–4903.
(22) Zhang, L.; Liu, Y.; Deng, L. Three-Coordinate Cobalt(IV) and Cobalt(V) Imido Complexes with N-Heterocyclic Carbene Ligation: Synthesis, Structure, and Their Distinct Reactivity in C–H Bond Amination. J. Am. Chem. Soc. 2014, 136 (44), 15525–15528.
(23) Zhang, H.; Ouyang, Z.; Liu, Y.; Zhang, Q.; Wang, L.; Deng, L. (Aminocarbene)(Divinyltetramethyldisiloxane)Iron(0) Compounds: A Class of Low-Coordinate Iron(0) Reagents. Angew. Chem. Int. Ed. 2014, 53 (32), 8432–8436.
(24) Hickey, A. K.; Lee, W.-T.; Chen, C.-H.; Pink, M.; Smith, J. M. A Bidentate Carbene Ligand Stabilizes a Low-Coordinate Iron(0) Carbonyl Complex. Organometallics 2016, 35 (17), 3069–3073.
(25) Cheng, J.; Chen, Q.; Leng, X.; Ouyang, Z.; Wang, Z.; Ye, S.; Deng, L. The Stabilization of Three-Coordinate Formal Mn(0) Complex with NHC and Alkene Ligation. Chem 2018, 4 (12), 2844–2860.
(26) Lavallo, V.; Canac, Y.; Präsang, C.; Donnadieu, B.; Bertrand, G. Stable Cyclic (Alkyl)(Amino)Carbenes as Rigid or Flexible, Bulky, Electron-Rich Ligands for Transition-Metal Catalysts: A Quaternary Carbon Atom Makes the Difference. Angew. Chem. Int. Ed. 2005, 44 (35), 5705–5709.
(27) Lavallo, V.; Canac, Y.; Donnadieu, B.; Schoeller, W. W.; Bertrand, G. CO Fixation to Stable Acyclic and Cyclic Alkyl Amino Carbenes: Stable Amino Ketenes with a Small HOMO–LUMO Gap. Angew. Chem. Int. Ed. 2006, 45 (21), 3488–3491.
(28) Samuel, P. P.; Neufeld, R.; Chandra Mondal, K.; Roesky, H. W.; Herbst-Irmer, R.; Stalke, D.; Demeshko, S.; Meyer, F.; Rojisha, V. C.; De, S.; Parameswaran, P.; Stückl, A. C.; Kaim, W.; Christian, J. H.; Bindra, J. K.; Dalal, N. S. Cr( I )Cl as Well as Cr + Are Stabilised between Two Cyclic Alkyl Amino Carbenes. Chem. Sci. 2015, 6 (5), 3148–3153.
(29) Samuel, P. P.; Mondal, K. C.; Roesky, H. W.; Hermann, M.; Frenking, G.; Demeshko, S.; Meyer, F.; Stückl, A. C.; Christian, J. H.; Dalal, N. S.; Ungur, L.; Chibotaru, L. F.; Pröpper, K.; Meents, A.; Dittrich, B. Synthesis and Characterization of a Two-Coordinate Manganese Complex and Its Reaction with Molecular Hydrogen at Room Temperature. Angew. Chem. Int. Ed. 2013, 52 (45), 11817–11821.
(30) Samuel, P. P.; Mondal, K. C.; Amin Sk, N.; Roesky, H. W.; Carl, E.; Neufeld, R.; Stalke, D.; Demeshko, S.; Meyer, F.; Ungur, L.; Chibotaru, L. F.; Christian, J.; Ramachandran, V.; van Tol, J.; Dalal, N. S. Electronic Structure and Slow Magnetic Relaxation of Low-Coordinate Cyclic Alkyl(Amino) Carbene Stabilized Iron(I) Complexes. J. Am. Chem. Soc. 2014, 136 (34), 11964–11971.
(31) Ung, G.; Rittle, J.; Soleilhavoup, M.; Bertrand, G.; Peters, J. C. Two-Coordinate Fe0 and Co0 Complexes Supported by Cyclic (Alkyl)(Amino)Carbenes. Angew. Chem. Int. Ed. 2014, 53 (32), 8427–8431.
(32) Mondal, K. C.; Roy, S.; De, S.; Parameswaran, P.; Dittrich, B.; Ehret, F.; Kaim, W.; Roesky, H. W. Stabilization of a Two-Coordinate Mononuclear Cobalt(0) Compound. Chem. – Eur. J. 2014, 20 (37), 11646–11649.
(33) Müller, C.; Andrada, D. M.; Bischoff, I.-A.; Zimmer, M.; Huch, V.; Steinbrück, N.; Schäfer, A. Synthesis, Structure, and Bonding Analysis of Tin(II) Dihalide and Cyclopentadienyltin(II) Halide (Alkyl)(Amino)Carbene Complexes. Organometallics 2019, 38 (5), 1052–1061.
(34) Horrer, G.; Krahfuß, M. J.; Lubitz, K.; Krummenacher, I.; Braunschweig, H.; Radius, U. N-Heterocyclic Carbene and Cyclic (Alkyl)(Amino)Carbene Complexes of Titanium(IV) and Titanium(III). Eur. J. Inorg. Chem. 2020, 2020 (3), 281–291.
(35) Schlüter, D.; Kleemiss, F.; Fugel, M.; Lork, E.; Sugimoto, K.; Grabowsky, S.; Harmer, J. R.; Vogt, M. Non-Oxido-Vanadium(IV) Metalloradical Complexes with Bidentate 1,2-Dithienylethene Ligands: Observation of Reversible Cyclization of the Ligand Scaffold in Solution. Chem. – Eur. J. 2020, 26 (6), 1335–1343.
(36) Stoffelbach, F.; Saurenz, D.; Poli, R. Improved Preparations of Molybdenum Coordination Compounds from Tetrachlorobis(Diethyl Ether)Molybdenum(IV). Eur. J. Inorg. Chem. 2001, 2001 (10), 2699–2703.
(37) Park, J. G.; Jeon, I.-R.; Harris, T. D. Electronic Effects of Ligand Substitution on Spin Crossover in a Series of Diiminoquinonoid-Bridged Fe II 2 Complexes. Inorg. Chem. 2015, 54 (1), 359–369.