[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-650803-105":3,"detail-sidebar-cat-0-en-105":80,"doc-detail-650803-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":73,"head_meta":75,"extra_data":77,"updated_unix":79},105,"en","chapter-17-five-coordination-introduction","Chapter 17 - Five Coordination - Introduction","","Chapter 17 focuses on “Five Coordination” in organometallic chemistry, explaining how molecular orbitals of complicated MLn complexes can be constructed from valence orbitals of smaller fragments. It develops a reductive approach in which orbitals of higher-symmetry ML6 or related fragments are transformed by systematically removing ligands to obtain C4v, C2v, and C3v ML5/ML4/ML3 fragments. The chapter emphasizes geometric and orbital perturbations, then details how removing one ligand from an octahedron affects the t2g, e, b2, and strongly stabilized a1 (z2) levels, including symmetry reduction and hybridization involving metal s and z characters.",{"@graph":14,"@context":72},[15,34,55],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/research-report/","Research & Report",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/chapter-17-five-coordination-introduction/650803/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/chapter-17-five-coordination-introduction/650803.png","ImageObject",300,407,{"name":42,"@type":43},"Genevieve","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-29","2026-10-24",true,{"@type":52,"interactionType":53,"userInteractionCount":30},"InteractionCounter",{"@type":54},"ViewAction",{"@type":56,"mainEntity":57},"FAQPage",[58,64,68],{"name":59,"@type":60,"acceptedAnswer":61},"How does the chapter build MLn molecular orbitals from smaller fragments?","Question",{"text":62,"@type":63},"It stresses constructing molecular orbitals from valence orbitals of smaller subunits. In the organometallic setting, MLn units are treated by generating a library of valence orbitals for common MLn fragments and relating them through symmetry changes and ligand removal.","Answer",{"name":65,"@type":60,"acceptedAnswer":66},"What is the reductive method illustrated in the chapter’s orbital correlation approach?",{"text":67,"@type":63},"The method starts from valence, metal-centered orbitals of a higher-symmetry fragment (octahedron/square plane) and then removes one or more ligands. This generates orbitals for lower-coordination fragments such as C4v ML5, C2v ML4, and C3v ML3, as shown in the discussion around Chart 17.1.",{"name":69,"@type":60,"acceptedAnswer":70},"What major orbital perturbation occurs when one ligand is removed from the octahedron to form the C4v ML5 fragment?",{"text":71,"@type":63},"To first approximation, the t2g set remains unaltered, but the key change involves the z2 component of the 2eg set. The a1 level (z2) becomes greatly stabilized and hybridized due to loss of antibonding interaction with the missing ligand and mixing of metal s and z characters.","https://schema.org",{"og:url":32,"og:type":74,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":76,"canonical":32},"index,follow",{"doc_id":78,"site_id":7},650803,1793152634,{"code":4,"msg":81,"data":82},"success",[83,87,91,95,100,105,110,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":84,"show_sort_weight":85,"slug":86},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":88,"show_sort_weight":89,"slug":90},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":92,"show_sort_weight":93,"slug":94},"Exam",70,"exam",{"id":96,"doc_module":4,"doc_module_name":25,"category_name":97,"show_sort_weight":98,"slug":99},5,"Comic",60,"comic",{"id":101,"doc_module":4,"doc_module_name":25,"category_name":102,"show_sort_weight":103,"slug":104},6,"Technology",50,"technology",{"id":106,"doc_module":4,"doc_module_name":25,"category_name":107,"show_sort_weight":108,"slug":109},7,"Healthcare",40,"healthcare",{"id":111,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":112,"slug":113},8,30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":96,"slug":129},19,"General","general",{"code":4,"msg":81,"data":131},{"doc_id":78,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":111,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":30,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":139,"language":140,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":12,"update_tm":144,"read_time":145},1374391974585,"https://ap-avatar.wpscdn.com/davatar_276721f389ce27ea32af1340a28f341c","C H A P T E R 1 7  \nFive Coordination  \n17.1 INTRODUCTION  \nThroughout this book, we have stressed one technique for understanding the molecular orbitals of complicated molecules, namely, their construction from the valence orbitals of smaller subunits. In the organometallic area, this is particularly useful since the molecules consist of an MLn unit bonded to some organic ligand. For this purpose, we need to build up a library of valence orbitals for common MLn fragments, where n ¼ 2–5and L isa generalized two-electrons donor ligand. We could do this by interacting an ensemble of Ln functions with a transition metal, just as was carried through for the octahedron (Section 15.1) and square plane (Section 16.1) cases. However, an easier method [1–3] starts with the valence, metal-centered orbitals of the octahedron and square plane. One or more ligands are then removed. This is illustrated in Chart 17.1. The valence orbitals of a C4v ML5 fragment, 17.2, can easily be derived by taking those of ML6, 17.1, and considering the perturbation induced by removing one ligand. A C2v ML4 species, 17.3, is derived by removing two cis ligands from ML6, and removal of three fac ligands will yield the C3v ML3 fragment, 17.4. We shall be primarily concerned with the geometry perturbation on going from 17.1 to 17.2 in this chapter. Now, those fragments, 17.2-17.3, can be distorted to give fragments of other types. For example, the C2v ML4 fragment can easily be distorted to aC4v structure, 17.5, ora tetrahedron. Likewise, wefind it useful to generate the levels of 17.6 from those of the square pyramid.  \nOnce the orbitals of a trigonal bipyramid have been derived, they can be used in turn to establish the orbitals of a C3v ML4 fragment like 17.7 which may then be distorted to a tetrahedron, and so on. Thus, the reductive approach illustrated in Chart 17.1 offers many ways to interrelate the orbitals of different systems. The fragments are interesting molecules in their own right, and we shall spend some time with their structure and dynamics. Our other starting point is the square plane, 17.8.  \nOrbital Interactions in Chemistry, Second Edition.  \nThomas A. Albright, Jeremy K. Burdett, and Myung-Hwan Whangbo.  \n􀀁 2013 John Wiley & Sons, Inc. Published 2013 by John Wiley & Sons, Inc.  \n466 17 FIVE COORDINATION  \nRemoval of one ligand gives a C2v ML3 fragment, 17.9. We shall see in Section 18.1 that the orbital structure of 17.9 is very similar to that of the C4v ML5 fragment, 17.2. Removing two cis ligands from 17.8 gives 17.10, with orbitals similar to those of 17.3. This correspondence between different MLn fragments is an important way to simplify and unify organometallic chemistry and forms a common thread running through Chapters 18–20.  \n17.2 THE C4V ML5 FRAGMENT  \nOn the left of Figure 17.1 are listed the metal-centered d blocks of orbitals for octahedral ML6. In Section 15.1 (see Figure 15.1), we established that there is a lower group of three levels, xz, yz, and xy, using the coordinate system at the top of Figure 17.1, which have t2g symmetry. These are filled for a saturated (18 electron) d6 complex. At much higher energy is the 2eg set. It will be empty in most organometallic examples and consists of x2 􀀂 y2 and z2 antibonding to the ligand lone pairs. When one ligand is removed from the octahedron [1], to a first approximation, the t2g set is left unaltered. The resultant levels are labeled as eþ b2 in the C4v point group of the fragment. No hybridization or energy change is introduced because the lone pair ofthe missing ligand is orthogonal to t2g. The same is true for the x2 􀀂 y2 component of 2eg. Suppose that the ligand removed from Cr(CO)6 was CO—ap acceptor [4]. Then, the xz and yz components of t2g would rise slightly in energy and xy is left untouched. Consequently, a relatively small energy gap will be introduced between e and b2. The major perturbation occurs with the z2 component of 2eg. That orbital, labeled a1 , will be g","cbCaigT27o0udUh3","https://ap.wps.com/l/cbCaigT27o0udUh3","pdf",7901529,38,"English","# 17.1 Introduction\n## Reductive approach from ML6/related fragments\n## Deriving C4v ML5, C2v ML4, and C3v ML3 fragments\n# 17.2 The C4v ML5 fragment\n## Orbital correlation from octahedron to square pyramid\n## Perturbations of t2g and 2eg sets after ligand removal\n## Stabilization and hybridization of the a1 (z2) orbital","[{\"question\":\"How does the chapter build MLn molecular orbitals from smaller fragments?\",\"answer\":\"It stresses constructing molecular orbitals from valence orbitals of smaller subunits. In the organometallic setting, MLn units are treated by generating a library of valence orbitals for common MLn fragments and relating them through symmetry changes and ligand removal.\"},{\"question\":\"What is the reductive method illustrated in the chapter’s orbital correlation approach?\",\"answer\":\"The method starts from valence, metal-centered orbitals of a higher-symmetry fragment (octahedron/square plane) and then removes one or more ligands. This generates orbitals for lower-coordination fragments such as C4v ML5, C2v ML4, and C3v ML3, as shown in the discussion around Chart 17.1.\"},{\"question\":\"What major orbital perturbation occurs when one ligand is removed from the octahedron to form the C4v ML5 fragment?\",\"answer\":\"To first approximation, the t2g set remains unaltered, but the key change involves the z2 component of the 2eg set. The a1 level (z2) becomes greatly stabilized and hybridized due to loss of antibonding interaction with the missing ligand and mixing of metal s and z characters.\"}]","Chapter 17 - Five Coordination - Introduction | PDF",1792846090,96]