Sulfur / carbon ligand bridged bimetallic complex, preparation method thereof and application of sulfur / carbon ligand bridged bimetallic complex in dehalogenation conversion of chlorine / brominated alkane into corresponding alkane or olefin

Abstract

The invention belongs to the technical field of preparation of metal complexes, and discloses a sulfur / carbon ligand bridged bimetallic complex, a preparation method thereof and an application of the sulfur / carbon ligand bridged bimetallic complex in dehalogenation conversion of chlorine / brominated alkane into corresponding alkane or olefin, thiophenol is used as a bridged ligand, and each metal center is coordinated with cyclopentadienyl or substituted cyclopentadienyl. And reacting the double halogen atom bridged bimetallic complex with thiophenol dilithium salt to obtain the sulfur / carbon ligand bridged bimetallic complex. The sulfur / carbon ligand bridged bimetallic complex provided by the invention can be used for dehalogenation conversion reaction of chlorine / brominated alkane under specific reaction conditions to obtain corresponding alkane or olefin, the reaction temperature is-78 to 40 DEG C, and the reaction time is 0.5 to 48 hours. According to the method, the reaction conditions are easy to control, the reaction temperature range is wide, the corresponding alkane or olefin and sulfur-bridged bimetallic dihalogen atom complex can be obtained, a new effective way is provided for resource utilization of chloro / brominated alkane, and the method has wide application prospects in the fields of organic synthesis, environmental governance and the like.

Description

Technical Field

[0001] This invention belongs to the field of metal complex preparation technology, specifically relating to sulfur / carbon ligand-bridged bimetallic complexes, their preparation methods, and their application in the dehalogenation of chloro / bromoalkanes into the corresponding alkanes or olefins. Background Technology

[0002] Chloroalkanes (CHPs) are important industrial solvents, adhesive components, and intermediates in organic synthesis, and are produced and used extensively worldwide. However, due to storage leaks and industrial wastewater discharges, they have become the most frequently detected volatile CHP pollutants in groundwater and soil. How to efficiently and environmentally convert waste or low-value CHPs into usable carbon sources has become a research hotspot in the field of green chemistry.

[0003] Transition metals have empty d orbitals, which can coordinate with the lone pairs of electrons of halogen atoms and the σ orbitals of C–X bonds. Through steps such as oxidative addition, metal–halogen bond formation, reductive elimination, and single electron transfer, the activation energy of C–X bond breaking is significantly reduced, enabling dehalogenation, degradation, and functional group transformation reactions that are originally difficult to occur to proceed efficiently under mild conditions.

[0004] Currently, dehalogenation methods for chloro / bromoalkanes mainly include catalytic hydrodehalogenation, reductive elimination reactions, and photocatalytic degradation. Most of these reactions rely on noble metals or electron-rich transition metal systems and are highly dependent on the synergistic effect of electron-donating ligands and reducing agents. The reaction conditions are harsh, and complete dehalogenation of chloro / bromoalkanes is difficult to achieve. Chem. Rev. 2019, 119 , 4471–4568; Chem. Soc. Rev. 2024, 53 , 263–316; Nature Water 2025, 3 , 1208–1218; Interdisciplinary Toxicol. 2016, 9 , 90–100; J. Am. Chem. Soc. 1996, 118 , 3029–3030; Organometallics 2015, 34 , 2255–2260.) Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention aims to provide two sulfur / carbon ligand-bridged bimetallic complexes, their preparation methods, and their application in the dehalogenation of chloro / bromoalkanes to the corresponding alkanes or alkenes. The sulfur / carbon ligand-bridged bimetallic complexes provided by this invention can activate chloro / bromoalkanes under mild conditions and convert them to the corresponding alkanes or alkenes.

[0006] The technical solution of the present invention is as follows: Sulfur / carbon ligand-bridged bimetallic complexes have the following structure: In structural formula I: R 1 Selected from cyclopentadiene ligand Cp and monomethylcyclopentadiene ligand Cp 1 dimethylcyclopentadiene ligand Cp 2 Trimethylcyclopentadiene ligand Cp 3 Tetramethylcyclopentadiene ligand Cp 4 Any one of pentamethylcyclopentadiene ligand Cp* and 1,2,4-tritert-butylcyclopentadiene ligand Cp'; Cp, Cp 1 Cp 2 Cp 3 Cp 4 Cp* and Cp' represent the following structures respectively: .

[0007] M is selected from any one of Cr, Mn, Fe, Co, and Ni.

[0008] In a preferred embodiment of the present invention, R 1 = Cp* or Cp′.

[0009] In another preferred embodiment, M = Co or Fe.

[0010] More preferably, R 1 = Cp* and M = Co; or R 1 = Cp* and M = Co.

[0011] A method for preparing sulfur / carbon ligand-bridged cobalt bis-cobalt complexes for dehalogenation conversion of chloro / bromoalkanes, following the route shown below: Among them, R 1 The definition of M is the same as above, and X = Cl or Br.

[0012] The specific preparation method is as follows: At -78 to 50 °C, 1 to 5 times the amount of thiophene dilithium salt and its derivatives were added to the dihalogen-bridged bimetallic complex and the reaction was carried out. After the temperature was raised to room temperature, the reaction was continued for 1 to 48 h to obtain sulfur / carbon ligand-bridged cobalt complex.

[0013] Preferably, the thiophene dilithium salt and its derivatives are thiophene dilithium salt or o-methylthiophene dilithium salt.

[0014] Preferably, the reaction occurs at carbon number C 10 The following ethers and benzenes have a carbon number of C 10 The following alkylbenzenes have 5 to 12 carbon atoms. 10 The reaction is carried out in any solvent containing alkanes, specifically chloro / bromoalkanes with 6 or fewer carbon atoms, with n-hexane being more preferred.

[0015] The method provided by this invention also includes a product purification step, such as distillation, extraction, filtration, etc. The purification steps are all common knowledge in the art and are well known to those skilled in the art, and will not be described in detail here.

[0016] Another object of the present invention is to provide the application of sulfur / carbon ligand-bridged bimetallic complexes for the dehalogenation conversion of chloro / bromoalkanes.

[0017] Sulfur / carbon ligand-bridged bimetallic complexes can directly achieve dehalogenation of chloro / bromoalkanes under the action of protic acids, yielding the corresponding alkanes or alkenes as well as sulfur-bridged bimetallic dihalogen complexes.

[0018] The obtained sulfur-bridged bimetallic dihalogen complex has the general structural formula shown in II: In structural formula II: R 1 The definitions of M and X are as described above. 1 =Cl or Br, R 2 = H or Me.

[0019] Y - To resist negative ions, it is selected from F - Cl - ,Br - I - PF6 - SbF6 - BF4 - BPh4 - CF3SO3 - and B(C6F5)4 - Any one of them; n is 1.

[0020] Table 1 lists some specific coordination compound structures, including: Cp, Cp 1 Cp 2 Cp 3 Cp 4 Cp* and Cp' represent the following structures: Table 1. Specific structures of sulfur-ligand-bridged dihalogen bimetallic complexes. Specifically, a method for achieving dehalogenation conversion of chloro / bromoalkanes using sulfur / carbon ligand-bridged cobalt complexes includes the following steps: In a nitrogen atmosphere, sulfur / carbon ligand-bridged cobalt complexes can directly achieve dehalogenation of chloro / bromoalkanes under the action of protic acids, yielding the corresponding alkanes or alkenes and sulfur-bridged cobalt dihalogen complexes. The reaction temperature is -100 to 25 °C, and the reaction time is 0.5 to 48 h.

[0021] Compared with the prior art, the advantages of the present invention are as follows: (1) This invention discloses for the first time a method for preparing a novel sulfur / carbon ligand-bridged bimetallic complex, providing new ideas and strategies for the design and development of bimetallic synergistic catalysts.

[0022] (2) This invention discloses for the first time a class of sulfur / carbon ligand-bridged bimetallic complexes that can mediate the dehalogenation of chlorinated / bromoalkanes to generate corresponding alkanes or alkenes under mild conditions, providing a novel solution for the efficient degradation of chlorinated / bromoalkanes.

[0023] Regarding the structure of coordination compounds, by rationally selecting R 1 The electronic and spatial structures of the complex can be precisely controlled, enhancing its adsorption and activation capabilities for chloro / bromoalkanes and improving the selectivity and activity of the dehalogenation conversion reaction. In terms of preparation, the reaction conditions are relatively mild, allowing for operation at lower temperatures, thus reducing energy consumption and equipment requirements. Raw material selection is flexible; the amount of thiophene dilithium salt and its derivatives can be adjusted within a certain range. A variety of solvents are available, with n-hexane being the preferred option due to its low cost and easy availability. The product purification process is simple, facilitating large-scale industrial production. In terms of applications, this complex can directly achieve the dehalogenation conversion of chloro / bromoalkanes under the action of protic acids. The reaction conditions are easily controlled, and the reaction temperature range is wide, yielding corresponding alkanes or alkenes, as well as sulfur-bridged bimetallic dihalogen complexes. This provides a new and effective pathway for the resource utilization of chloro / bromoalkanes and has broad application prospects in organic synthesis, environmental remediation, and other fields. Attached Figure Description

[0024] Figure 1 The crystal structure of complex A in Example 1 is shown. Figure 2 The crystal structure of complex B in Example 2 is shown. Figure 3 The crystal structure of complex 1 in Example 3 is shown. Figure 4 The crystal structure of complex 2 in Example 4; Figure 5 The crystal structure of complex 3 in Example 5; Figure 6 The crystal structure of complex 4 in Example 6 is shown. Detailed Implementation

[0025] The following embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the invention in any way. Unless otherwise specified, the experimental methods used in the present invention are conventional methods, and the experimental equipment, materials, reagents, etc. used are all commercially available.

[0026] The following describes the specific preparation methods of the two main complexes of this invention, the specific operations for achieving the dehalogenation conversion of chloro / bromoalkanes, and the separation method of sulfur-bridged dicobalt dihalogen atom complexes.

[0027] Example 1: Preparation of sulfur / carbon ligand-bridged cobalt bis-cobalt complex A At -78 °C, 2.50 g of thiophene dilithium salt (10.00 mmol) was added to [Cp*Co( m In a hexane solution containing [-Br)₂CoCp*](4.98 g, 10.00 mmol), the solution changed from dark red to brownish-yellow as the reaction temperature was slowly increased from -78 °C to room temperature. After filtration, the reaction solution was concentrated under vacuum and frozen at -78 °C for 12 h. The precipitated solid was collected and dried under vacuum to obtain a light brownish-yellow solid powder [Cp*Co( m - or 2 : or 3 [-C6H4S)CoCp*] (A, 3.72 g, 7.50 mmol), yield 75%. Crystals suitable for X-ray single-crystal diffraction can be obtained by crystallization by volatilization of n-hexane. 1 HNMR (400 MHz, CD2Cl2, ppm, 298 K): 1.71 (s, 30H, Cp*-C H 3), 6.32 (d, J 1 = 7.75 Hz, 1H, Ph- H ), 6.87 (d, J1 = 6.47 Hz, 1H, Ph- H ), 6.94 (d, J 1 = 5.62 Hz, 1H, Ph- H ), 7.83 (d, J 1 = 6.44 Hz, 1H, Ph- H ). 13 C NMR (100 MHz, CD2Cl2, ppm, 298K): 10.8 (Cp*- C H3), 85.7 (Cp*- C ), 114.9 (Ph- C ), 121.6 (Ph- C ), 122.9 (Ph- C ),126.7 (Ph- C ), 133.6 (Ph- C ), 145.1 (Ph- C IR (KBr, cm) -1 ): 729, 1022, 1375,1452, 1637, 2850, 2901, 2960, 3011, 3049. Anal. Calcd. For: C, 62.90; H, 6.90. Found: C, 62.79; H, 7.27. Example 2 Preparation of sulfur / carbon ligand-bridged cobalt bis-cobalt complex B At -78 °C, 1.25 g (10.00 mmol) of bis(o-methylthiophenol) was added to [Cp*Co( m In a hexane solution containing [-Br)₂CoCp*] (4.98 g, 10.00 mmol), the solution changed from dark red to light green as the reaction temperature was slowly increased from -78 °C to room temperature. After filtration, the reaction solution was concentrated under vacuum to obtain a dark green solid powder [Cp*Co( m - or 2 : or 2 -C7H5S)( m [-H)CoCp*] (B, 4.08 g, 7.50 mmol), yield 80%. Crystals suitable for X-ray single-crystal diffraction can be obtained by crystallization by evaporation of diethyl ether. 1 H NMR (600 MHz, CD2Cl2, ppm, 298 K): 1.64(s, 30H, Cp*-C H 3), 5.94 (dd, J 1 = 8.54 Hz, J 2 = 7.11 Hz, 1H, Ph- H ), 6.23 (d, J 1 = 7.53 Hz, 1H, Ph- H ), 6.26 (dd, J 1 = 7.94 Hz, J 2 = 7.11 Hz, 1H, Ph- H ), 6.52(d, J 1 = 6.49 Hz, 1H, Ph- H ). 13 C NMR (100 MHz, CD2Cl2, ppm, 298 K): 10.8(Cp*- C H3), 85.7 (Cp*- C ), 114.9, 121.6, 122.9, 133.6, 145.1 (Ph- C ), 126.7 ( C H- C IR (KBr, cm) -1 ): 745, 1025, 1379, 1435, 1497, 2852, 2885, 2903, 2968. Anal.Calcd. For: C, 63.52; H, 7.11. Found: C, 63.39; H, 7.57. Example 3: Dehalogenation of dichloromethane using sulfur / carbon ligand-bridged cobalt-1 complex to obtain sulfur-bridged cobalt-1 chloride complex 1 At -78 °C, 55.8 μL of HBF4 Et2O (55% wt, 0.30 mmol) was added dropwise to 10 mL of a dichloromethane solution of complex A (148.5 mg, 0.30 mmol). As the reaction temperature was slowly increased from -78 °C to room temperature, the solution changed from brownish-yellow to emerald green. After filtration, the reaction solution was concentrated under vacuum to obtain a dark green crystalline powder [Cp*Co( m -SPh)( m[-Cl)2CoCp*] (1, 122 mg, 0.215 mmol), yield 72%. Crystals suitable for X-ray single-crystal diffraction were obtained by dichloromethane / n-hexane dual-solvent diffusion crystallization. 1 H NMR (400 MHz, CDCl3, ppm, 298 K): 1.10 (s, 30H, Cp*-C H 3), 8.24 (d, J 1 = 8.36 Hz, 2H, Ph- H ), 7.57 (t, J 1 = 7.47Hz, 1H, Ph- H ), 7.44 (t, J 1 = 7.46 Hz, 2H, Ph- H ). 13 C NMR (100 MHz, CDCl3, ppm, 298 K): 9.7 (Cp*- C H3), 92.5 (Cp*- C ), 133.9, 130.4, 129.3, 129.2 (Ph- C IR(KBr, cm) -1 ): 518, 698, 762, 1047, 1377, 1439, 1575, 2922, 2970, 3052. Anal.Calcd. For: C, 47.66; H, 5.38. Found: C, 47.62; H, 5.85. Example 4: Dehalogenation of dibromomethane using sulfur / carbon ligand-bridged cobalt-2 complexes yields sulfur-bridged cobalt-2 bromine-2 complexes. At -60 °C, HBF4 Et2O (37.2 μL, 55% wt, 0.20 mmol) was added dropwise to 10 mL of a dibromomethane solution of complex A (99.2 mg, 0.20 mmol). As the reaction temperature was slowly increased from -60 °C to room temperature, the solution changed from brownish-yellow to emerald green. After filtration, the reaction solution was concentrated under vacuum to obtain a dark green crystalline powder [Cp*Co( m -SPh)( m [-Br)₂CoCp*] (2, 89.4 mg, 0.136 mmol), yield 68%. Crystals suitable for X-ray single-crystal diffraction were obtained by dichloromethane / n-hexane dual-solvent diffusion crystallization.1 H NMR (400 MHz, CDCl3, ppm, 298 K): 1.10 (s, 30H, Cp*-C H 3), 8.30 (d, J 1 = 6.56 Hz, 2H, Ph- H ), 7.59 (t, J 1 = 7.58 Hz, 1H, Ph- H ), 7.45 (t, J 1 = 7.68 Hz, 2H, Ph- H ). 13 C NMR (100 MHz, CDCl3,ppm, 298 K): 9.7 (Cp*- C H3), 92.4 (Cp*- C ), 134.0, 130.4, 129.3, 129.2 (Ph- C IR (KBr, cm) -1 ): 520, 698, 762, 1055, 1375, 1470, 1575, 2923, 2996, 3052. Anal. Calcd. For: C, 41.97; H, 4.74. Found: C, 42.34; H, 5.30. Example 5: Dehalogenation of dichloromethane using sulfur / carbon ligand-bridged cobalt-3 complexes yielded sulfur-bridged cobalt-2-chloro complex 3. At -78 °C, HBF4 Et2O (18.6 μL, 55% wt, 0.10 mmol) was added dropwise to 10 mL of a dichloromethane solution of complex B (51.0 mg, 0.10 mmol). As the reaction temperature was slowly increased from -78 °C to room temperature, the solution changed from light green to emerald green. After filtration, the reaction solution was concentrated under vacuum to obtain a dark green crystalline powder [Cp*Co( m -SC7H7)( m [-Cl)2CoCp*] (3, 45.3 mg, 0.078 mmol), yield 78%. Crystals suitable for X-ray single-crystal diffraction were obtained by dichloromethane / n-hexane dual-solvent diffusion crystallization. 1 H NMR (400 MHz, CDCl3, ppm, 298 K): 1.08 (s, 30H, Cp*-C H 3), 2.97 (s, 3H, Me- H ), 8.35 (d, J 1 = 7.93 Hz, 2H, Ph- H ), 7.47 (t, J 1 = 7.22 Hz, 1H, Ph- H ), 7.41 (t, J 1 = 7.24 Hz, 1H, Ph- H ), 7.27(t, J 1 = 7.48 Hz, 2H, Ph- H ). 13 C NMR (100 MHz, CD2Cl2, ppm, 298 K): 9.64(Cp*- C H3), 92.6 (Cp*- C ), 145.9, 133.5, 132.9, 131.5, 130.0, 127.4, (Ph- C ),22.5 (Me- C ), IR (KBr, cm -1 ): 556, 842, 1018, 1372, 1455, 1632, 2851, 2920,2965. Anal. Calcd. For: C, 44.58; H, 5.13. Found: C, 44.20; H, 5.08. Example 6: Dehalogenation conversion of dibromomethane using sulfur / carbon ligand-bridged cobalt-2 complexes yields sulfur-bridged cobalt-2 bromine complex 4. At -60 °C, HBF4 Et2O (37.2 μL, 55% wt, 0.20 mmol) was added dropwise to 10 mL of a dibromomethane solution of complex B (102.0 mg, 0.20 mmol). As the reaction temperature was slowly increased from -60 °C to room temperature, the solution changed from light green to emerald green. After filtration, the reaction solution was concentrated under vacuum to obtain a dark green crystalline powder [Cp*Co( m -SC7H7)( m [-Br)₂CoCp*] (4, 90.2 mg, 0.134 mmol), yield 67%. Crystals suitable for X-ray single-crystal diffraction were obtained by dichloromethane / n-hexane dual-solvent diffusion crystallization. 1H NMR (400 MHz, CDCl3, ppm, 298 K): 1.22 (s, 30H, Cp*-C H 3), 2.98 (s, 3H, Me- H ), 8.44 (d, J 1 = 7.94 Hz, 2H, Ph- H ), 7.48 (t, J 1 = 7.23 Hz, 1H, Ph- H ), 7.41 (d, J 1 = 7.45 Hz, 2H, Ph- H ),7.31 (t, J 1 = 7.49 Hz, 2H, Ph- H ). 13 C NMR (100 MHz, CD2Cl2, ppm, 298 K): 9.9(Cp*- C H3), 92.5 (Cp*- C ), 145.9, 134.9, 133.8, 131.6, 130.0, 127.5 (Ph- C ),22.6 (Me- C ), IR (KBr, cm -1 ): 518, 698, 762, 1047, 1377, 1439, 1575, 2922,2970, 3052. Anal. Calcd. For: C, 39.73; H, 4.57. Found: C, 39.43; H, 4.80. The structures of coordinations A, B, 1, 2, 3, and 4 were characterized by X-ray single-crystal diffraction (instrument used: Brüker SmartApex CCD single-crystal diffractometer). Important crystallographic data are shown in Tables 2, 3, and 4, and the main structural parameters are shown in Tables 5-10. Their crystal structures are as follows: Figure 1-6 As shown.

[0028] Table 2 Crystallographic data of coordination compounds A and B Table 3 Crystallographic data of coordinations 1 and 2 Table 4 Crystallographic data of coordinations 3 and 4 Table 5. Major bond lengths and bond angles of complex A Table 6. Major bond lengths and bond angles of coordination compound B Table 7. Major bond lengths and bond angles of complex 1 Table 8. Main bond lengths and bond angles of complex 2 Table 9. Main bond lengths and bond angles of complex 3 Table 10. Major bond lengths and bond angles of complex 4 Example 7: Complex A mediates the dehalogenation of dichloromethane / dibromomethane to methane. Complex A (99.2 mg, 0.20 mmol), HBF4·Et2O (96 mg, 0.20 mmol), and other compounds were added. 0.60 mmol) of methane and dichloromethane / dibromomethane (5 mL) were added to a Schlenk flask. After the reaction was completed, 1.00 mL of gas was quantitatively extracted from the top of the flask through the gas sampling port. The product was identified as methane by Agilent gas chromatograph. The yield of methane was calculated to be 0.052 mmol according to the standard curve, with a yield of 52%.

[0029] Example 8: Complex A activates 1,2-dichloroethane to produce ethylene. Complex A (49.6 mg, 0.10 mmol), HBF4·Et2O (16... 0.10 mmol) of 1,2-dichloroethane and 5 mL of ethylene were added to a Schlenk flask. After the reaction was completed, 1.00 mL of gas was quantitatively extracted from the top of the flask through the gas sampling port. The product was identified as ethylene by Agilent gas chromatograph. The yield of ethylene was calculated to be 0.078 mmol according to the standard curve, with a yield of 78%.

[0030] Example 9: Complex B activates dichloromethane / dibromomethane to produce methane. Complex A (49.6 mg, 0.10 mmol), HBF4·Et2O (48 mg, 0.10 mmol) were added. L (0.30 mmol) and dichloromethane / dibromomethane (5 mL) were added to a Schlenk flask. After the reaction was completed, 1.00 mL of gas was quantitatively extracted from the top of the reaction flask through the gas sampling port. The product was identified as methane by Agilent gas chromatograph. The yield of methane was calculated to be 0.029 mmol according to the standard curve, with a yield of 58%.

[0031] Example 10: Complex B activates 1,2-dichloroethane to produce ethylene. Complex B (99.2 mg, 0.20 mmol), HBF4·Et2O (32 mg, 0.20 mmol) were added. 0.20 mmol) and 1,2-dichloroethane (5 mL) were added to a Schlenk flask. After the reaction was completed, 1.00 mL of gas was quantitatively extracted from the top of the flask through the gas sampling port. The product was identified as ethylene by Agilent gas chromatograph. The yield of ethylene was calculated to be 0.146 mmol according to the standard curve, with a yield of 73%.

[0032] Under mild conditions (e.g., <200°C, atmospheric pressure), the C–Cl bond activation of dichloromethane typically leads to non-selective conversions of alkanes and alkenes, while direct deep hydrogenation and dechlorination to methane often results in low selectivity (<30%). Therefore, the methane selectivity of Examples 7-10 is significantly higher than typical values, representing a major breakthrough.

[0033] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A sulfur / carbon ligand-bridged bimetallic complex, characterized in that, The general structural formula is I: ， R 1 Selected from cyclopentadiene ligand Cp and monomethylcyclopentadiene ligand Cp 1 dimethylcyclopentadiene ligand Cp 2 Trimethylcyclopentadiene ligand Cp 3 Tetramethylcyclopentadiene ligand Cp 4 Any one of pentamethylcyclopentadiene ligand Cp* and 1,2,4-tritert-butylcyclopentadiene ligand Cp'; Cp, Cp 1 Cp 2 Cp 3 Cp 4 Cp* and Cp' represent the following structures respectively: ； M is selected from any one of Cr, Mn, Fe, Co, and Ni.

2. The sulfur / carbon ligand-bridged bimetallic complex according to claim 1, characterized in that, R 1 = Cp* or Cp′, M = Co or Fe.

3. The sulfur / carbon ligand-bridged bimetallic complex according to claim 1, characterized in that, R 1 = Cp* and M = Co; or R 1 = Cp* and M = Co.

4. A method for preparing a sulfur / carbon ligand-bridged cobalt bis-cobalt complex for dehalogenation conversion of chloro / bromoalkanes, characterized in that, Prepared according to the following route: ， Among them, R 1 The definition of M is as described in claim 1, where X = Cl or Br; Specific preparation methods include: At -78 to 50 °C, 1 to 5 times the amount of thiophene dilithium salt and its derivatives were added to the dihalogen-bridged bimetallic complex and the reaction was carried out. After the temperature was raised to room temperature, the reaction was continued for 1 to 48 h to obtain sulfur / carbon ligand-bridged cobalt complex.

5. The method for preparing sulfur / carbon ligand-bridged cobalt bis-cobalt complexes for dehalogenation conversion of chloro / bromoalkanes according to claim 4, characterized in that, The dilithium salt of thiophenol and its derivatives are dilithium salt of thiophenol or o-methylthiophenol dilithium salt.

6. The method for preparing sulfur / carbon ligand-bridged cobalt bis-cobalt complexes for dehalogenation conversion of chloro / bromoalkanes according to claim 4, characterized in that, The reaction occurs at carbon number C 10 The following ethers and benzenes have a carbon number of C 10 The following alkylbenzenes have 5 to 12 carbon atoms. 10 The reaction is carried out in any solvent of alkanes, specifically chloro / bromoalkanes with 6 or fewer carbon atoms.

7. The method for preparing sulfur / carbon ligand-bridged cobalt bis-cobalt complexes for dehalogenation conversion of chloro / bromoalkanes according to claim 4 or 6, characterized in that, The solvent is n-hexane; the process also includes a product purification step, which includes at least one of distillation, extraction, and filtration.

8. An application of a sulfur / carbon ligand-bridged bimetallic complex, characterized in that, The complex is used for the dehalogenation conversion of chloro / bromoalkanes.

9. The application of the sulfur / carbon ligand-bridged bimetallic complex as described in claim 8, characterized in that, Sulfur / carbon ligand-bridged bimetallic complexes can directly achieve dehalogenation transformation of chloro / bromoalkanes under the action of protic acids, yielding the corresponding alkanes or alkenes, as well as sulfur-bridged bimetallic dihalogen complexes. The general structural formula of sulfur-bridged bimetallic dihalogen complexes is shown in II: R 1 The definitions of M and X are as described in claim 1. 1 =Cl or Br, R 2 = H or Me, Y - To resist negative ions, it is selected from F - Cl - ,Br - I - PF6 - SbF6 - BF4 - BPh4 - CF3SO3 - and B(C6F5)4 - Any one of the following, where n is 1.

10. The application of the sulfur / carbon ligand-bridged bimetallic complex as described in claim 9, characterized in that, The dehalogenation conversion of chloro / bromoalkanes takes place at temperatures ranging from -100 to 25 °C for 0.5 to 48 h.

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