UNIVERSITI MALAYA UNIVERSITY OF MALAYA PEPERIKSAAN IJAZAH SARJANA MUDA SAINS EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE PEPERIKSAAN IJAZAH SARJANA MUDA SAINS DENGAN PENDIDIKAN EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE WITH EDUCATION SESI AKADEMIK 2014/2015 : SEMESTER 2 ACADEMIC SESSION 2014/2015 : SEMESTER 2 SCES3110 : KIMIA TAKORGANIK III INORGANIC CHEMISTRY III Jun 2015 June 2015 Masa : 2 jam Time : 2 hours ARAHAN KEPADA CALON : INSTRUCTIONS TO CANDIDATES : Kertas soalan ini mengandungi Bahagian A dan B. This paper consists of Section A and B. Jawab soalan mengikut arahan yang diberikan dalam setiap bahagian. Questions should be answered according to the instructions given in each section. (Kertas ini mengandungi 4 soalan dalam 7 halaman yang dicetak) (This question paper consists of 4 questions on 7 printed pages)
BAHAGIAN A ( 66 MARKAH) SECTION A ( 66 MARKS) Jawab SEMUA soalan dalam Bahagian ini Answer ALL questions in this Section 1. (a) Disiklopentadiena dipecahkan terlebih dahulu dalam tindak balas retro- Diels-alder menghasil monomer C 5 H 6 di mana mudah deprotonatkan dengan logam alkali memberi natrium siklopentadienid, NaCp: Dicyclopentadiene has first to be cracked in a retro-diels-alder reaction to give monomeric C 5 H 6 which can be easily deprotonated by alkali metals to give sodium cyclopentadienide, NaCp. (i) Nyatakan dengan ringkas penyediaan molibdolosen dengan menggunakan NaCp bersama dengan reagen lain yang sesuai. Briefly describe the preparation of molybdolocene by using NaCp together with other suitable reagents. (ii) Apakah ikatan yang terlibat dalam molibdolosen? What are the bondings involved in molybdolocene? (iii) Lukiskan isomer molibdolosen dan pencirian spektroskopinya. Draw the isomers of molybdolocene and describe spectroscopic characterizations. (b) Tentukan bilangan elektron pada W, Mo dan Pt bagi kompleks yang berikut: Specify the electron count at W, Mo and Pt in the following complexes: (i) 2/7
(ii) (iii) Struktur molekul [PtMe(bhq)( -dppy)au(pph 3 )]PF 6 dimana bhq=benzokuinolina, dppy=2-difenilfosfinopiridina. Anion PF 6 dan atom hidrogen tidak dimasukkan. Molecular structure of [PtMe(bhq)( -dppy)au(pph 3 )]PF 6, where bhq=benzoquinoline, dppy=2-diphenylphosphinopyridine. Anions PF 6 and hydrogen atoms are omitted. (c) Spektrum 1 H-RMN ( 1 -C 5 H 5 )( 5 -C 5 H 5 )Fe(CO) 2 diberi seperti berikut. Terangkan sifat logam-c 5 H 5 dalam kompleks ini dalam pelbagai suhu dan lukiskan strukturnya. The 1 H-NMR spectrum of ( 1 -C 5 H 5 )( 5 -C 5 H 5 )Fe(CO) 2 is given below. Explain the metal-c 5 H 5 behavior of the complex at various temperatures and draw the structures. 3/7
1 H-NMR spectrum of ( 1 -C 5 H 5 )( 5 -C 5 H 5 )Fe(CO) 2 (60 MHz) (30 markah/marks) 2. Berikan hasil dan tuliskan persamaan yang terlibat bagi tindak balas yang berikut: Give the product and write the reactions involved in the following reactions: a) Tindak balas tambahan BuLi pada MeCN merupakan kaedah yang mudah untuk penyediaan keton. Addition reaction of BuLi to MeCN is a versatile method for the preparation of ketone. b) Tindak balas tambahan regiospesifik alkilsilan, Me 3 Si(CH 2 CH=CH 2 ) kepada sebatian karbonil, RR C=O dalam tindak balas Sakurai menghasil alilalkohol. (Reagen (n-bu) 4 N + F - digunakan untuk membentuk perantaraan anion alil). Tuliskan mekanisme tindak balas ini. In the regiospecific addition of the alkylsilane, Me 3 Si(CH 2 CH=CH 2 ) to carbonyl compound, RR C=O in the Sakurai reaction has lead to formation of an allylalcohol. (Reagent (n-bu) 4 N + F - was used to generate the intermediate, allyl anion). Write the mechanisms involved in this reaction. c) Tetrafenilborat dalam lantanid logamlosen, [(C5Me5)2Ln][(μ-Ph)2BPh2] (Ln = Y, 1atau Sm, 2) pada mulanya berkoordinat pada logam Ln, kemudiaan menurunkannya membolehkan interaksi logam-substrat sebelum penurunan. Substrat seperti NaN3, aseton atau azobenzene terkoordinat kepada kompleks lanthanide ini. 4/7
The tetraphenylborate in the lanthanide metallocene, [(C5Me5)2Ln][(μ- Ph)2BPh2] (Ln = Y, or Sm, ) was initially coordinated to the metal; then undergoes reduction with elemental Ln to probe metal-substrate interactions prior to reduction. substrates such as NaN3, acetone or azobenzene was coordinated to the lanthanide complex. d) Lukiskan struktur hasil daripada tindak balas yang berikut: Draw the structures of the products from the following reactions: (i) (ii) (iii) (iv) Tindak balas TiCl 3 dengan Na(C 5 H 5 ) membentuk dimer dengan titian fulvalenedieil dan hydrida. Reaction of TiCl 3 with Na(C 5 H 5 ) leads to the formation of a dimer with a fulvalenedieyl bridge and hydride bridges. Fullerenol, C 60 (OH) 12-14 mudah bertindak balas dengan alkoksi silan, R 3 SiH melalui tindak balas transesterifikasi dan gantian membentuk adduk. Fullerenol, C 60 (OH) 12-14 can be reacted easily with alkoxy silane R 3 SiH through transesterification and displacement reactions to form adducts. n-butil lithium bertindak balas dengan fenil isosianat, Ph-N=C=O menghasil sebatian siklik. n-butyl lithium reacts with phenyl isocyanate, Ph-N=C=O to give the cyclized product. Pentafluorofenol, C 6 F 5 OH bertindak balas dengan sililamida, Ln[N(SiMe 3 ) 2 ] 3 sama ada dalam benzen, dietil eter atau methanol. Pentafluorophenol, C 6 F 5 OH reacts with silylamides Ln[N(SiMe 3 ) 2 ] 3 in either benzene, diethyl ether or methanol. (36 markah/marks) 5/7
BAHAGIAN B ( 34 MARKAH) SECTION B ( 34 MARKS) Jawab SEMUA soalan Answer ALL questions 3. (a) Kompleks kromium spin tinggi, [Cr(H 2 O) 2+ 6, menukarkan air terkoordinat pada kadar sangat tinggi dimana k ex melebihi 10 8 s -1. Jelaskan fenomena ini. The high spin chromium compleks, [Cr(H 2 O) 2+ 6, exchanges its coordinated water at a very high rate of exchange whereby k ex is in excess of 10 8 s -1. Account for this phenomenum. (b) Huraikan mekanisme penukargantian bagi [NiCl 4 ] 2- bertetrahedron. Apakah parameter- parameter luar-kinetik yang perlu diambil bagi memastikan mekanisme ini. Describe the mechanism of substitution of tetrahedral [NiCl 4 ] 2-. What extrakinetic parameters should be taken to ascertain the mechanism? (c) Bagi hidrolisis: For the hydrolysis: [Co(NH 3 ) 5 X] 2+ + H 2 O = [Co(NH 3 ) 5 (H 2 O)] 3+ + Cl - dimana X = I, Br, Cl atau F where X = I, Br, Cl or F pemalar kadar hidrolisis mengikut tertib the rate constant for hydrolysis is in the order Terangkan tren ini. Explain this trend. k obs : I - > Br - > Cl - > F - (d) Apakah yang dikenali sebagai kesan trans? What is known as the trans effect? Bermula dengan [PtCl 4 ] 2-, NO 2 - and NH 3, sediakan cis- [PtCl 2 (NO 2 )(NH 3 )] - Starting with [PtCl 4 ] 2-, NO 2 - and NH 3, prepare cis- [PtCl 2 (NO 2 )(NH 3 )] -. 6/7
Siri kesan trans NO 2 - > Cl - > NH 3 Trans effect series NO 2 - > Cl - > NH 3 (e) Beri ulasan mengenai mekanisme pemindahan bagi Comment on the electron transfer mechanism for V 2+ (ak) + VO 2+ (ak) = 2V 3+ (ak). 4. Jawap samada (a) atau (b) sahaja. Answer either (a) or (b) only. (a) (b) Tuliskan nota-nota mengenai faktor-faktor yang memberi kesan keatas pemindahan elektron melalui mekanisme sfera luar. Berikan sekurangkurangnya dua contoh tindakbalas pemindahan elektron melalui mekanisme sfera luar bagi menerangkan jawapan anda. Write notes on the factors that affect electron transfer via the outer sphere mechanism. Give at least two examples of electron transfer reaction via the outer sphere mechanism to illustrate your answer. Tuliskan nota-nota bagi hidrolisis bermangkinkan asid yang melibatkan kompleks logam peralihan. Berikan contoh-contoh. Write notes on the acid catalysed hydrolysis involving transition metal complexes. Give examples. (9 markah/marks) TAMAT END 7/7