laboratory presentation slide prepared by group 5 member. For inorganic chemistry laboratory course, SSC UTM skudai. we enjoy our presentation.

1. GROUP MEMBERS: NG MEI XIANG NOOR HIDAYAH MOHD JUSOH LEE YEE VOON NORADILA AWANG MOHD NORULAKMAL AB MALIK EXPERIMENT 5: IDENTIFICATION OF STEREOCHEMICAL ISOMERS OF [Mo(CO) 4 (L) 2 ] BY INFRARED SPECTROSCOPY

9. Mo(CO) 6 (1.0g)Weighted + 40ml dry heptane + 5ml piperidine + few pieces boiling stones & magnetic stirring bar Filter precipitate while hot Wash twice with 10 ml (60-80  C) petroleum ether that has been cooled 1)Weight 2)Calculate the % yield 3) Record IR Heated for two hours (reflux temp= 110 o C-120 o C) with stirring. Suck dry by vacuum pump

10. 0.5g Mo(CO 4 )(pip) 2 + 20ml dichloromethane in N 2 + 0.75g PPh 3 -> Reflux for 20 mins Cool to room temperature Filter orange solution by gravity filtration Concentrate filtrate by rotary evaporator Collect by pump filtration Add 8 drops methanol Solution put in ice bath first, then cooled in freezer (<0 o C) for 15 minutes 1)Weight 2)Calculate the % yield 3) Record IR

11. 0.5g molybdenum carbonyl complex+ 10ml dry toluene under N 2 -> Reflux for 30 minutes Cool to room temperature Reduce volume on rotary evaporator Purify the product by 10ml dichloromethane Collect product by gravity filtration Concentrate the filtrate, collect precipitate Weight product, calculate % yield, and record IR

13. (A) Synthesis of [Mo(CO) 4 (HNC 5 H 10 ) 2 ] Table 1: Data from Infrared Spectrum [Mo(CO) 4 (HNC 5 H 10 ) 2 ] Weight of product = 1.14g Colour of product = Yellow colour Melting point = 125 0 C Percentage yield = 79.72% Functional Group Wavenumber, cm -1 N-H (°2 amine) 3264.59 C-H (sp 3 stretching) 2926.20, 2855.26 C = O stretching 1839.16, 1890.44,1995.98, 2011.68

14. ( B) Synthesis of cis-[Mo(CO) 4 (PPh 3 ) 2 ] Table 2: Data from Infrared Spectrum cis-[Mo(CO) 4 (PPh 3 ) 2 ] Weight of product = 0.84g Colour of product = Pale yellow Melting point = 160 0 C– 165 0 C Percentage yield = 86.60% Functional Group Wavenumber, cm -1 C-H (sp 2 stretching) 2925.34 C = O stretching 1827.84,1871.46, 2012.45 C=C stretching 1461.50

15. (C) Synthesis of trans-[Mo(CO) 4 (PPh 3 ) 2 ] Table 3: Data from Infrared Spectrum trans-[Mo(CO) 4 (PPh 3 ) 2 ] Weight of product = 0.44g Colour of product = Brownish off-white Melting point = 163 0 C-168 0 C Percentage yield = 88% Functional Group Wavenumber, cm -1 C-H (sp 2 stretching) 2924.79 C = O stretching 1889.17, 1947.80,2021.88,2071.59 C=C stretching 1463.91, 1585.12

23. The S N 2 mechanism of formation [Mo(CO) 4 (HNC 5 H 10 ) 2 ] is shown as following : intermediate Cis-[Mo(CO) 4 (HNC 5 H 10 ) 2 ] Mo CO CO CO CO OC OC + pip pip------Mo(CO) 5 ----CO Mo CO CO CO OC OC pip slow + Mo CO CO CO OC OC pip pip Mo CO CO OC OC pip pip

26. Pale yellow precipitate formed

28. The reaction for the formation of cis-[Mo(CO) 4 (PPh 3 ) 2 ] complex by using S N 1 mechanism. Cis-isomer Mo CO CO OC OC pip Mo CO CO OC OC + PPh 3 Mo CO CO OC OC PPh 3 PPh 3 PPh 3 PPh 3 Mo CO CO OC OC pip pip Mo CO CO OC OC pip + PPh 3 Mo CO CO OC OC pip PPh 3

32. Brownish off-white precipitate was [Mo(CO) 4 (PPh 3 ) 2 ]

34. The reaction of dissociation mechanism for the formation of trans-[Mo(CO) 4 (PPh 3 ) 2 ] complex by using S N 1 mechanism.