Kertas ini mengandungi Bahagian A dan Bahagian B. This examination paper consists of sections A and B.

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1 UNIVERSITI MALAYA UNIVERSITY OF MALAYA PEPERIKSAAN IJAZAH SARJANA MUDA SAINS EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE SESI AKADEMIK 2012/2013 : SEMESTER 2 ACADEMIC SESSION 2012/2013 : SEMESTER 2 SCES3110 : Kimia Takorganik III Inorganic Chemistry III Jun 2013 June 2013 Masa : 2 jam Time : 2 hours ARAHAN KEPADA CALON: INSTRUCTIONS TO CANDIDATES: Kertas ini mengandungi Bahagian A dan Bahagian B. This examination paper consists of sections A and B. Jawab soalan mengikut arahan yang diberikan dalam setiap bahagian. Questions should be answered according to the instruction given in each section.. (Kertas ini mengandungi 5 soalan dalam 6 halaman yang dicetak) (This question paper consists of 5 questions on 6 printed pages)

2 BAHAGIAN A (66 markah) SECTION A (66 marks) Jawab SEMUA soalan. Answer ALL questions. 1. (a) Kompleks karbena, [(CO) 5 Cr=C(CH 3 )(OCH 3 )] boleh disediakan daripada tindak balas tambahan alkillitium kepada Cr(CO) 6. Nyatakan sintesis ini. The carbene complex, [(CO) 5 Cr=C(CH 3 )(OCH 3 )] can be prepared from the addition of an alkyllithium to Cr(CO) 6. Describe this synthesis. (b) Bandingkan dan nyatakan pengikatan dalam logamlosen, [(η 5 -C 5 H 5 ) 2 M] dimana M = Nb, Be atau Ln. Compare and describe the bonding in the metallocenes, [(η 5 -C 5 H 5 ) 2 M] where M = Nb, Be or Ln. Tentukan bilangan elektron pada Co, Re dan Rh bagi kompleks yang berikut: Specify the electron count at Co, Re and Rh in the following complexes: (i) (ii) (iii) (19 markah/marks) 2/6

3 2. Kenal pastikan A hingga G bagi tindak balas yang berikut: Identify A to G for the following reactions: n-buli H 2 O O 2 (a) Piridina A B C Pyridine -H 2 O (dimana C = piridina 2-tertukarganti) (where C = 2-substituted pyridine) HBF 4 - C 5 H 6 Ni(C 5 H 5 ) 2 (b) Ni(C 5 H 5 ) 2 D E F 14 VE (dimana VE = elektron valens dan F = kompleks berlapis multideker) (where VE = valence electron and F = multidecker sandwich complex) Tindak balas logam karbonil dalam bes kuat menghasilkan anion karbonil logam (karbonilmetalat). Fe(CO) 5 bertindak balas dengan akueus NaOH menghasil G yang menunjukkan satu puncak tunggal di 1 H NMR pada -11 ppm. The reaction of a metal carbonyl in strong base gives metal carbonyl anion (carbonylmetallate). Fe(CO) 5 reacts with aqueous NaOH to yield G which shows a single 1 H NMR peak at -11 ppm. (18 markah/marks) 3. Lukiskan struktur hasil tindak balas yang berikut: Draw the structures of the products arising from the following reactions: (a) (C 5 H 5 ) 2 Fe bertindak balas dengan n-buli dan kemudian dengan Ph 2 PCl. (C 5 H 5 ) 2 Fe reacts with n-buli and then with Ph 2 PCl. (b) Pengabstrakan hidrida di (C 5 H 5 )(CO) 2 Fe-C(H)(CH 3 ) 2 dengan [CPh 3 ]BF 4. Hydride abstraction from (C 5 H 5 )(CO) 2 Fe-C(H)(CH 3 ) 2 with [CPh 3 ]BF 4. Tindak balas (Ph 3 P) 2 Pt(R 2 C=CR 2 ) dengan C 2 Ph 2. Reaction of (Ph 3 P) 2 Pt(R 2 C=CR 2 ) with C 2 Ph 2. (8 markah/marks) SCES3110 3/6

4 4 (a) Protodesililatan menyerupai penukargantian aromatik berelektrofil. Apakah hasil tindak balas jika (C 6 H 5 )SiMe 3 bertindak balas dengan elektrofil seperti ICl dan dengan CH 3 COCl/AlCl 3? Tuliskan kedua-dua tindak balas ini. Protodesilylation resembles electrophilic aromatic substitutions. What are the products if (C 6 H 5 )SiMe 3 reacts with electrophiles such as ICl and with CH 3 COCl/AlCl 3? Write the equations for both reactions. (b) Tindak balas termal campuran ekuimolar C 60, Pt(dba) 2 (dba = dibenzilideneaseton) dan (η 6 -Ph 2 PC 6 H 5 ) 2 Cr dalam toluene pada suhu bilik menghasil kompleks fulleren dualogam Pt/Cr. Lukiskan struktur ini. Thermal reaction of an equimolar mixture of C 60, Pt(dba) 2 (dba = dibenzylideneacetone) and (η 6 -Ph 2 PC 6 H 5 ) 2 Cr in toluene at room temperature afforded a bimetallic Pt/Cr fullerene complex. Draw the structures. Kompleks taktersolvat [(C 5 Me 5 ) 2 Ln][(μ-Ph) 2 BPh 2 ], logamlosen tidak terikat kuat dengan ion tetrafenilborat dan mudah diganti dengan molekul seperti azid dan keton. Berikan hasil bagi setiap tindak balas [(C 5 Me 5 ) 2 Ln][(μ- Ph) 2 BPh 2 ] dengan 1 ekuivalen NaN 3 dan dengan (CH 3 ) 2 C=O. In the unsolvated [(C 5 Me 5 ) 2 Ln][(μ-Ph) 2 BPh 2 ] complexes, the metallocene is only loosely ligated with the tetraphenylborate ion and can easily be displaced by molecules like azide and ketone. Give the products for each of the reaction of [(C 5 Me 5 ) 2 Ln][(μ-Ph) 2 BPh 2 ] with 1 equivalent NaN 3 and with (CH 3 ) 2 C=O. (8 markah/marks) 4/6

5 BAHAGIAN B (34 markah) SECTION B (34 marks) Jawab SEMUA soalan. Answer ALL questions. 5. (a) Tindakbalas berikut berlaku melalui mekanisme interchange. Terbitkan hukum kadarnya. The following reaction proceeds via an interchange mechanism. Derive the rate law. [Cr(H 2 O) 6 ] 3+ + SCN - { [Cr(H 2 O) 6 ], NCS} 2+ {[Cr(H 2 O) 6 ], NCS} 2+ [Cr(H 2 O) 5 NCS] 2+ + H 2 O (b) Mekanisme yang manakah paling berjaya menghuraikan profil tindakbalas (tenaga potensi tindakbalas lawan koordinat tindakbalas)? Huraikan ciri utama plot ini. Which mechanism best describes the reaction profile (potential energy of reactants against reaction coordinate)? Describe the main features of this plot. Apakah yang dimaksudkan dengan kesan- trans? Bermula samada dengan [PtCl 4 ] 2- or [Pt(NH 3 ) 4 ] 2+, huraikan penyediaan cis-platin dan transplatin (platin = [PtCl 2 (NH 3 ) 2 ]. What is known as the trans- effect? Starting with either [PtCl 4 ] 2- or [Pt(NH 3 ) 4 ] 2+, describe the preparation of cis-platin and trans-platin (platin = [PtCl 2 (NH 3 ) 2 ]. Kesan Trans Cl - > NH 3. Trans effect of Cl - > NH 3 (3 markah/marks) 5/6

6 (d) Pt(II) dikelaskan seperti asid lembut. Susunkan kadar tindakbalas diantara Pt(II) dan ion tersenarai dibawah. Beri sebab bagi susunan anda. Nilai nukleofilisiti adalah Pt(II) is classified as a soft acid. Arrange the rates of reaction between Pt(II) and the ions listed below. Give your reasons for such an arrangement. Nucleophilicity values are F Cl Br I (e) Berbezaan dalam panjang ikatan pemindahan elektron diantara [Co(NH 3 ) 6 ] 2+ dan [Co(NH 3 ) 6 ] 3+ ialah 0.18Å. Pada asas ini, adakah anda jangka pemindahan elektron diantara kedua-dua ion menjadi tinggi atau rendah? Apakah faktor-faktor lain yang menyumbang kepada kadar pemindahan elektron? The difference in bond lengths for the electron transfer between [Co(NH 3 ) 6 ] 2+ and [Co(NH 3 ) 6 ] 3+ is 0.18Å. On this basis, do you expect the rate of electron transfer between these two ions to be high or low? What other factor contributes to the rate of electron transfer? (f) Jawab samada (i) atau (ii). Answer either (i) or (ii). (i) (ii) Apakah keperluan-keperluan khas bagi tindakbalas mekanisme sfera dalam? Terangkan dengan memberi contoh-contoh. What are the essential requirements for an inner sphere reaction mechanism? Illustrate with examples. Tuliskan nota-nota ringkas mengenai tindakbalas pada kedudukan tetrahedral bagi kompleks-kompleks logam tak organik. Write short notes on substitution reactions at tetrahedral sites for inorganic metal complexes. (11 markah/marks) ***TAMAT*** ***END*** 6/6