{"id":13335,"date":"2026-05-09T06:01:17","date_gmt":"2026-05-09T06:01:17","guid":{"rendered":"https:\/\/www.vedprep.com\/exams\/?p=13335"},"modified":"2026-05-09T06:01:17","modified_gmt":"2026-05-09T06:01:17","slug":"metal-carbonyls-bonding","status":"publish","type":"post","link":"https:\/\/www.vedprep.com\/exams\/gate\/metal-carbonyls-bonding\/","title":{"rendered":"Master Metal carbonyls (bonding and structure) For GATE 2026"},"content":{"rendered":"<p><strong>Metal carbonyls<\/strong> are coordination compounds of transition metals with carbon monoxide as a ligand.<\/p>\n<h2>Syllabus &#8211; Inorganic Chemistry for GATE (CHE-201)<\/h2>\n<p>The topic of metal carbonyls, specifically their bonding and structure, falls under the unit of <strong>Inorganic Chemistry <\/strong>(CHE-201) in the <a href=\"https:\/\/gate2026.iitg.ac.in\/\" rel=\"nofollow noopener\" target=\"_blank\">GATE exam<\/a> syllabus. This unit is also relevant to CSIR NET and IIT JAM examinations. Coordination compounds and transition metals are closely related topics that are often covered in conjunction with metal carbonyls.<\/p>\n<p>Students preparing for these exams can refer to standard textbooks such as <em>Physical Chemistry <\/em>by Peter Atkins and <em>Inorganic Chemistry <\/em>by Catherine E. Housecroft and Alan G. Sharpe. These textbooks provide comprehensive coverage of inorganic chemistry, including metal carbonyls, their bonding, and structure.<\/p>\n<p>Key areas of focus in this unit include the definition and properties of coordination compounds, the role of transition metals in these compounds, and the various types of bonds that can form between metal centers and ligands. Understanding these concepts is essential for success in the GATE exam and other related chemistry exams.<\/p>\n<ul>\n<li>Coordination compounds<\/li>\n<li>Transition metals<\/li>\n<\/ul>\n<h2>Metal carbonyls (bonding and structure) For GATE: Definition and Importance<\/h2>\n<p>Metal carbonyls are a class of coordination compounds that consist of transition metals bonded to carbon monoxide (CO) ligands. In these compounds, the metal atom is bonded to one or more CO molecules through a combination of sigma donation and pi-backbonding. <strong>Sigma donation <\/strong>refers to the donation of electron density from the CO ligand to the metal atom, while <em>pi-back bonding <\/em>involves the back-donation of electron density from the metal atom to the CO ligand.<\/p>\n<p>Pi-backbonding is a crucial aspect of metal carbonyl chemistry, as it helps to stabilize the metal-CO bond. This type of bonding occurs when the metal atom donates electron density to the pi* orbitals of the CO ligand, which are antibonding orbitals that are oriented perpendicular to the metal-CO bond axis. As a result of pi-backbonding, the metal-CO bond acquires some degree of <strong>covalent character<\/strong>, leading to increased stability.<\/p>\n<p>Metal carbonyls play a significant role in <strong>synthetic organic chemistry <\/strong>and <em>homogeneous catalysis<\/em>. They are used as catalysts in various reactions, such as the hydrogenation of unsaturated compounds and the carbonylation of olefins. The ability of metal carbonyls to facilitate these reactions is directly related to their bonding and structural properties. Understanding the chemistry of metal carbonyls is essential for GATE and other competitive exams in chemistry.<\/p>\n<h2>Worked Example: Ni(CO)4<\/h2>\n<p>Nickel tetracarbonyl, Ni(CO)4, is a zerovalent nickel complex with a tetrahedral geometry. This complex is an important example of a metal carbonyl, where the metal atom is bonded to four carbon monoxide (CO) ligands. The tetrahedral geometry of Ni(CO)4 is a result of the sp3 hybridization of the nickel atom.<\/p>\n<p>The metal-carbon bond length in Ni(CO)4 is 1.83 \u00c5, which is a characteristic feature of metal carbonyls. This bond length is a result of the significant backbonding from the nickel atom to the CO \u03c0* orbitals, which weakens the C-O bond and strengthens the Ni-C bond.<\/p>\n<p>To understand the metal-carbon bond order in Ni(CO)4, it is essential to consider the molecular orbital (MO) diagram of the complex. The MO diagram shows that the Ni-C bond order is 3, indicating a significant degree of backbonding from the nickel atom to the CO ligands. This backbonding is responsible for the stability of the complex.<\/p>\n<p><strong>Question:<\/strong>What is the hybridization of the nickel atom in Ni(CO)4, and what is the metal-carbon bond order?<\/p>\n<p><strong>Solution:<\/strong>The nickel atom in Ni(CO)4 undergoes sp3 hybridization, resulting in a tetrahedral geometry. The metal-carbon bond order is 3, which is a result of the significant backbonding from the nickel atom to the CO \u03c0* orbitals.<\/p>\n<p>The table below summarizes the key features of Ni(CO)4:<\/p>\n<table>\n<tbody>\n<tr>\n<th>Property<\/th>\n<th>Value<\/th>\n<\/tr>\n<tr>\n<td>Geometry<\/td>\n<td>Tetrahedral<\/td>\n<\/tr>\n<tr>\n<td>Metal-carbon bond length<\/td>\n<td>1.83 \u00c5<\/td>\n<\/tr>\n<tr>\n<td>Metal-carbon bond order<\/td>\n<td>3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Understanding the bonding and structure of metal carbonyls, such as Ni(CO)4, is crucial for <em>Metal carbonyls (bonding and structure) For GATE <\/em>and other competitive exams, including CSIR NET and IIT JAM. Students should focus on the key concepts, including hybridization, backbonding, and molecular orbital theory.<\/p>\n<h2>Common Misconception: Metal carbonyls are only used in catalysis<\/h2>\n<p>Students often assume that metal carbonyls are solely used in catalysis. This understanding is incorrect as metal carbonyls have a broader range of applications. They are also used in synthetic organic chemistry, where they serve as precursors to synthesize complex organic molecules.<\/p>\n<p>One notable example is the Mond process, which involves the reaction of nickel with carbon monoxide to produce nickel carbonyl. This process is then used to purify nickel.<strong>Metal carbonyls (bonding and structure) For GATE <\/strong>is an essential topic to understand such industrial processes. The Mond process illustrates the use of metal carbonyls in extractive metallurgy.<\/p>\n<p>In organometallic chemistry, metal carbonyls are used as precursors to synthesize a wide range of organometallic compounds. For instance, <code>Fe(CO)5<\/code> is used to prepare <code>Fe(CO)4<\/code> and other iron-based organometallic compounds. Some common applications of metal carbonyls include:<\/p>\n<ul>\n<li>homogeneous catalysis<\/li>\n<li>synthesis of complex organic molecules<\/li>\n<li>precursors in organometallic chemistry<\/li>\n<\/ul>\n<p>Understanding the bonding and structure of metal carbonyls is crucial to appreciate their diverse applications. Metal carbonyls exhibit a range of bonding modes, including terminal, bridging, and semi-bridging carbonyls. This knowledge is essential for GATE and other competitive exams, where questions on metal carbonyls are frequently asked.<\/p>\n<h2>Application: Hydroformylation of Alkenes<\/h2>\n<p>Hydro formylation, also known as the <em>oxo process<\/em>, is a widely used industrial process that converts alkenes into aldehydes. This reaction is a crucial step in the production of various chemicals, such as plastics and other materials. The process involves the addition of carbon monoxide and hydrogen to an alkene, resulting in the formation of an aldehyde.<\/p>\n<p>In this process, <strong>rhodium-based catalysts<\/strong>, such as RhH(CO)(PPh3)3, play a vital role. These catalysts facilitate the reaction by coordinating with the alkene, carbon monoxide, and hydrogen, thereby enabling the formation of the aldehyde. The use of these catalysts allows for a more efficient and selective reaction, which is essential for industrial applications.<\/p>\n<p>The hydroformylation reaction is used to produce a wide range of aldehydes, including <code>butanal<\/code> and <code>propanal<\/code>, which are used as intermediates in the production of plastics, detergents, and other chemicals. This reaction operates under relatively mild conditions, with temperatures ranging from 50\u00b0C to 150\u00b0C and pressures between 10 and 100 bar.<\/p>\n<p>The hydroformylation process has numerous applications in the chemical industry, particularly in the production of <strong>polyethylene <\/strong>and <strong>polypropylenev <\/strong>plastics. Its efficiency and selectivity make it a valuable process in various industrial settings.<\/p>\n<h2>Exam Strategy: Focus on Coordination Compounds and Transition Metals<\/h2>\n<h2>Metal carbonyls (bonding and structure) For GATE: Real-World Applications<\/h2>\n<p>Metal carbonyls are organometallic complexes consisting of a metal atom bonded to one or more carbon monoxide (CO) ligands. These compounds have numerous applications in various industries. One significant use of metal carbonyls is in the production of nickel and other metals. For instance, nickel carbonyl,<code>Ni(CO)4<\/code>, is used in the Mond process to produce high-purity nickel.<\/p>\n<p>Metal carbonyls are also employed as precursors in organometallic chemistry. They serve as a source of metal atoms in various reactions. <strong>Precursor <\/strong>refers to a compound that can be converted into another compound through a chemical reaction. In the context of metal carbonyls, precursors are used to generate metal complexes with specific properties. For example-, <code>Ni(CO)4<\/code> is used as a precursor to <code>Ni(0)<\/code> complexes, which are essential in catalytic reactions.<\/p>\n<p>The applications of metal carbonyls can be summarized as follows:<\/p>\n<ul>\n<li>Production of nickel and other metals<\/li>\n<li>Precursors in organometallic chemistry<\/li>\n<li>Generation of metal complexes with specific properties<\/li>\n<\/ul>\n<p>Understanding the bonding and structure of metal carbonyls is crucial for their applications. The <em>synergistic effect <\/em>of multiple CO ligands on the metal center leads to a unique bonding situation, which is essential for their reactivity. Students preparing for GATE, CSIR NET, and IIT JAM exams should focus on grasping these concepts to tackle related questions.<\/p>\n<h2>VedPrep Tips: Focus on Understanding the Mechanism<\/h2>\n<p>Understanding the mechanism of metal carbonyl formation is crucial for mastering this topic. The process involves the coordination of a carbon monoxide (CO) ligand to a metal center, resulting in a complex with unique bonding characteristics. Students should focus on the role of pi-backbonding in metal carbonyl bonding, which is a critical aspect of their stability.<\/p>\n<p>Pi-backbonding, also known as backbonding, is a type of bonding where electrons from the metal center are transferred to the antibonding \u03c0* orbitals of the CO ligand. This phenomenon is essential for understanding the properties and reactivity of metal carbonyls. A thorough grasp of this concept can be gained through expert guidance, such as that provided by VedPrep, which offers free video resources, including lectures on metal carbonyls.<\/p>\n<p>To prepare effectively for the exam, students should practice problems and past year questions, which helps to reinforce their understanding of the topic. A recommended study method involves reviewing the fundamental concepts, such as the <strong>18-electron rule <\/strong>and <em>ligand field theory<\/em>, and then applying them to solve problems. VedPrep provides students with the necessary resources and expert guidance to excel in this topic.<\/p>\n<p>Some frequently tested subtopics include:<\/p>\n<ul>\n<li>The structure and bonding of metal carbonyls<\/li>\n<li>The role of pi-backbonding in metal carbonyl stability<\/li>\n<li>The application of the 18-electron rule in predicting metal carbonyl formation<\/li>\n<\/ul>\n<p>By following these study tips and utilizing <a href=\"https:\/\/www.vedprep.com\/\">VedPrep&#8217;s resources<\/a>, students can develop a deep understanding of metal carbonyls and be well-prepared for their exams.<\/p>\n<section class=\"vedprep-faq\">\n<h2>Frequently Asked Questions<\/h2>\n<div class=\"faq-item\">\n<style>#sp-ea-15294 .spcollapsing { height: 0; overflow: hidden; transition-property: height;transition-duration: 300ms;}#sp-ea-15294.sp-easy-accordion>.sp-ea-single {margin-bottom: 10px; border: 1px solid #e2e2e2; }#sp-ea-15294.sp-easy-accordion>.sp-ea-single>.ea-header a {color: #444;}#sp-ea-15294.sp-easy-accordion>.sp-ea-single>.sp-collapse>.ea-body {background: #fff; color: #444;}#sp-ea-15294.sp-easy-accordion>.sp-ea-single {background: #eee;}#sp-ea-15294.sp-easy-accordion>.sp-ea-single>.ea-header a .ea-expand-icon { float: left; color: #444;font-size: 16px;}<\/style><div id=\"sp_easy_accordion-1778306262\">\n<div id=\"sp-ea-15294\" class=\"sp-ea-one sp-easy-accordion\" data-ea-active=\"ea-click\" data-ea-mode=\"vertical\" data-preloader=\"\" data-scroll-active-item=\"\" data-offset-to-scroll=\"0\">\n\n<!-- Start accordion card div. -->\n<div class=\"ea-card ea-expand sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152940\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152940\" aria-controls=\"collapse152940\" href=\"#\"  aria-expanded=\"true\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-minus\"><\/i>  What are Metal Carbonyls?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse collapsed show\" id=\"collapse152940\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152940\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>&nbsp;<\/p>\n<p><b>Metal carbonyls<\/b><span style=\"font-weight: 400\"> are <\/span><b>coordination compounds<\/b><span style=\"font-weight: 400\"> in which transition metals are bonded to <\/span><b>carbon monoxide (CO) ligands<\/b><span style=\"font-weight: 400\">. The metal atom forms bonds with one or more CO molecules through a combination of <\/span><b>sigma donation<\/b><span style=\"font-weight: 400\"> (electron donation from CO to metal) and <\/span><b>pi-backbonding<\/b><span style=\"font-weight: 400\"> (electron back-donation from metal to CO). They are essential organometallic complexes tested frequently in GATE exams.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152941\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152941\" aria-controls=\"collapse152941\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is Sigma Donation in Metal Carbonyls?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152941\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152941\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><b>Sigma (\u03c3) donation<\/b><span style=\"font-weight: 400\"> refers to the <\/span><b>transfer of electron density from the CO ligand to the metal atom<\/b><span style=\"font-weight: 400\">. In this bonding interaction, the carbon atom of CO donates electrons from its \u03c3 orbital to empty orbitals on the metal center. This donation strengthens the metal-CO bond and is the first component of metal carbonyl bonding, essential for understanding GATE questions.<\/span><\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152942\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152942\" aria-controls=\"collapse152942\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is Pi-Backbonding in Metal Carbonyls?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152942\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152942\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><b>Pi-backbonding<\/b><span style=\"font-weight: 400\"> (or <\/span><b>\u03c0-backbonding<\/b><span style=\"font-weight: 400\">) is the <\/span><i><span style=\"font-weight: 400\">back-donation of electron density from the metal atom to the \u03c0 (antibonding) orbitals of the CO ligand<\/span><\/i><span style=\"font-weight: 400\">*. This interaction:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>Weakens the C-O bond<\/b><span style=\"font-weight: 400\"> - increases C-O bond length<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Strengthens the M-C bond<\/b><span style=\"font-weight: 400\"> - increases metal-carbon bond order<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Stabilizes the complex<\/b><span style=\"font-weight: 400\"> - crucial for metal carbonyl stability Pi-backbonding is the key factor determining metal carbonyl stability and reactivity.<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152943\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152943\" aria-controls=\"collapse152943\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the Structure of Ni(CO)\u2084?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152943\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152943\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><b>Nickel tetracarbonyl [Ni(CO)\u2084]<\/b><span style=\"font-weight: 400\"> has:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>Geometry<\/b><span style=\"font-weight: 400\">: Tetrahedral (4 CO ligands around Ni)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Hybridization<\/b><span style=\"font-weight: 400\">: sp\u00b3 on nickel atom<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Ni-C bond length<\/b><span style=\"font-weight: 400\">: 1.83 \u00c5<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Ni-C bond order<\/b><span style=\"font-weight: 400\">: 3 (due to significant \u03c0-backbonding)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Oxidation state<\/b><span style=\"font-weight: 400\">: Nickel is in 0 state (Ni\u2070) Ni(CO)\u2084 is a classic example of a stable metal carbonyl with 18 valence electrons.<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152944\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152944\" aria-controls=\"collapse152944\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Why Do Metal Carbonyls Follow the 18-Electron Rule?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152944\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152944\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span style=\"font-weight: 400\">Metal carbonyls typically have <\/span><b>18 valence electrons<\/b><span style=\"font-weight: 400\"> because:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>Stability<\/b><span style=\"font-weight: 400\">: 18-electron configuration gives noble gas-like stability<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Valence electrons<\/b><span style=\"font-weight: 400\"> = metal electrons + ligand electron donations<\/span><\/li>\n<li style=\"font-weight: 400\"><b>CO ligands donate 2 electrons each<\/b><span style=\"font-weight: 400\"> to the metal center For example, <\/span><b>Ni(CO)\u2084<\/b><span style=\"font-weight: 400\">: Ni contributes 10 electrons + 4 CO ligands contribute 8 electrons = 18 total electrons, providing maximum stability.<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152945\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152945\" aria-controls=\"collapse152945\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the Bond Order in Metal-Carbonyl Bonds?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152945\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152945\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span style=\"font-weight: 400\">The metal-carbonyl bond has a <\/span><b>bond order of 3<\/b><span style=\"font-weight: 400\">, composed of:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>1 \u03c3 bond<\/b><span style=\"font-weight: 400\"> from CO to metal (sigma donation)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>2 \u03c0 bonds<\/b><span style=\"font-weight: 400\"> from metal to CO (pi-backbonding into \u03c0* orbitals) This high bond order (3) explains:<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Short bond length<\/b><span style=\"font-weight: 400\"> (1.83 \u00c5 in Ni(CO)\u2084)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>High bond strength<\/b><span style=\"font-weight: 400\"> - difficult to break<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Stability of the complex<\/b><span style=\"font-weight: 400\"> - resistant to decomposition<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152946\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152946\" aria-controls=\"collapse152946\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What are the Common Geometries of Metal Carbonyls?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152946\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152946\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Common geometries include:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>Tetrahedral<\/b><span style=\"font-weight: 400\">: Ni(CO)\u2084 (4 CO ligands)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Trigonal bipyramidal<\/b><span style=\"font-weight: 400\">: Fe(CO)\u2085 (5 CO ligands)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Octahedral<\/b><span style=\"font-weight: 400\">: Cr(CO)\u2086 (6 CO ligands)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Trigonal planar<\/b><span style=\"font-weight: 400\">: planar complexes with 3 CO ligands The geometry depends on the <\/span><b>number of CO ligands<\/b><span style=\"font-weight: 400\"> and the <\/span><b>steric requirements<\/b><span style=\"font-weight: 400\"> of achieving 18 valence electrons.<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152947\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152947\" aria-controls=\"collapse152947\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the Mond Process?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152947\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152947\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span style=\"font-weight: 400\">The <\/span><b>Mond process<\/b><span style=\"font-weight: 400\"> is an <\/span><b>industrial metallurgical process<\/b><span style=\"font-weight: 400\"> that:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>Produces high-purity nickel<\/b><span style=\"font-weight: 400\"> from nickel ore<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Uses nickel carbonyl [Ni(CO)\u2084]<\/b><span style=\"font-weight: 400\"> as an intermediate<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Involves equilibrium<\/b><span style=\"font-weight: 400\">: Ni + 4CO \u21cc Ni(CO)\u2084<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Low temperature decomposition<\/b><span style=\"font-weight: 400\"> returns pure Ni metal This demonstrates a major industrial application of metal carbonyls, frequently tested in GATE exams.<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152948\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152948\" aria-controls=\"collapse152948\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What are the Different Carbonyl Bonding Modes?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152948\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152948\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span style=\"font-weight: 400\">Metal carbonyls exhibit different bonding modes:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><b>Terminal carbonyls<\/b><span style=\"font-weight: 400\">: Single CO bonded to one metal center (most common)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Bridging carbonyls<\/b><span style=\"font-weight: 400\">: CO bridges two metal centers (\u03bc-CO)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Semi-bridging carbonyls<\/b><span style=\"font-weight: 400\">: CO partially bridges metal atoms<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Chelating carbonyls<\/b><span style=\"font-weight: 400\">: CO acts as a ligand through multiple interaction points Understanding these bonding modes is essential for predicting metal carbonyl structure and reactivity in GATE questions.<\/span><\/li>\n<\/ul>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-152949\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse152949\" aria-controls=\"collapse152949\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> How is the 18-Electron Rule Applied to Metal Carbonyls?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse152949\" data-parent=\"#sp-ea-15294\" role=\"region\" aria-labelledby=\"ea-header-152949\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span style=\"font-weight: 400\">To apply the 18-electron rule to metal carbonyls:<\/span><\/p>\n<ol>\n<li style=\"font-weight: 400\"><b>Count metal valence electrons<\/b><span style=\"font-weight: 400\"> (group number - oxidation state)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Count electron donations from CO ligands<\/b><span style=\"font-weight: 400\"> (2 electrons per CO)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Adjust for complex charge<\/b><span style=\"font-weight: 400\"> (add electrons for negative charges, subtract for positive)<\/span><\/li>\n<li style=\"font-weight: 400\"><b>Total should equal 18<\/b><span style=\"font-weight: 400\"> for stability Example: <\/span><b>Cr(CO)\u2086<\/b><span style=\"font-weight: 400\">: Cr\u2070 (6e\u207b) + 6 CO (12e\u207b) = 18 electrons \u2713<\/span><\/li>\n<\/ol>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<\/div>\n<\/div>\n\n<\/div>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Metal carbonyls are coordination compounds of transition metals with carbon monoxide as a ligand. The topic of metal carbonyls falls under the unit of Inorganic Chemistry in the GATE exam syllabus. Coordination compounds and transition metals are closely related topics.<\/p>\n","protected":false},"author":12,"featured_media":13334,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","rank_math_seo_score":85},"categories":[31],"tags":[2923,8826,8827,8828,8829,2922],"class_list":["post-13335","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-gate","tag-competitive-exams","tag-metal-carbonyls-bonding-and-structure-for-gate","tag-metal-carbonyls-bonding-and-structure-for-gate-notes","tag-metal-carbonyls-bonding-and-structure-for-gate-questions","tag-metal-carbonyls-bonding-and-structure-for-gate-syllabus","tag-vedprep","entry","has-media"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/13335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/comments?post=13335"}],"version-history":[{"count":4,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/13335\/revisions"}],"predecessor-version":[{"id":15295,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/13335\/revisions\/15295"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media\/13334"}],"wp:attachment":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media?parent=13335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/categories?post=13335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/tags?post=13335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}