{"id":23139,"date":"2019-03-08T17:46:15","date_gmt":"2019-03-08T10:46:15","guid":{"rendered":"http:\/\/tom.ji42.com\/?p=23139"},"modified":"2019-03-08T17:46:15","modified_gmt":"2019-03-08T10:46:15","slug":"the-definition-of-ortho-meta-and-para-in-organic-chemistry","status":"publish","type":"post","link":"https:\/\/tom.tomwork.net\/?p=23139","title":{"rendered":"The Definition of ‘Ortho,’ ‘Meta,’ and ‘Para’ in Organic Chemistry"},"content":{"rendered":"

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The terms\u00a0ortho<\/em>,\u00a0meta<\/em>, and\u00a0para<\/em>\u00a0are\u00a0prefixes used in organic chemistry<\/a>\u00a0to indicate the position of non-hydrogen substituents on a hydrocarbon ring (benzene derivative). The prefixes derive from Greek words\u00a0meaning\u00a0correct\/straight, following\/after, and similar, respectively. Ortho, meta, and para\u00a0historically carried different meanings, but in 1879 the American Chemical Society settled upon the following definitions, which remain in use today.<\/p>\n<\/div>\n<\/div>\n

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<\/div>\n

<\/a><\/p>\n

Ortho<\/span><\/h3>\n
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Ortho\u00a0describes a\u00a0molecule with\u00a0substituents<\/a>\u00a0at the 1 and 2 positions on an\u00a0aromatic compound<\/a>. In other words, the substituent is adjacent or next to the primary carbon on the ring.<\/p>\n<\/div>\n

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The symbol for ortho\u00a0is o- or 1,2-<\/p>\n<\/div>\n<\/div>\n

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<\/div>\n<\/div>\n
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<\/div>\n

<\/a><\/p>\n

Meta<\/span><\/h3>\n
\n

Meta\u00a0is used to describe a\u00a0molecule<\/a>\u00a0with\u00a0substituents are at the 1 and 3 positions on an\u00a0aromatic compound.<\/p>\n

The symbol for\u00a0meta is\u00a0m-\u00a0or\u00a01,3<\/p>\n<\/div>\n<\/div>\n

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<\/div>\n<\/div>\n
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<\/div>\n

<\/a><\/p>\n

Para<\/span><\/h3>\n
\n

Para\u00a0describes\u00a0a\u00a0molecule\u00a0with\u00a0substituents at the 1 and 4 positions on an\u00a0aromatic compound<\/a>. In other words, the substituent is directly opposite the primary carbon of the ring.<\/p>\n

The symbol for\u00a0para\u00a0is\u00a0p-\u00a0or\u00a01,4-<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

The terms\u00a0ortho,\u00a0meta, and\u00a0para\u00a0are\u00a0prefixes used in organic chemistry\u00a0to indicate the position of non-hydrogen substituents on a hydrocarbon ring (benzene derivative). The prefixes derive from Greek words\u00a0meaning\u00a0correct\/straight, following\/after, and similar, respectively. Ortho, meta, and para\u00a0historically carried different meanings, but in 1879 the American Chemical Society settled upon the following definitions, which remain in use today.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[6],"tags":[],"class_list":["post-23139","post","type-post","status-publish","format-standard","hentry","category-6"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p6cOVM-61d","_links":{"self":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts\/23139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=23139"}],"version-history":[{"count":1,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts\/23139\/revisions"}],"predecessor-version":[{"id":23141,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=\/wp\/v2\/posts\/23139\/revisions\/23141"}],"wp:attachment":[{"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tom.tomwork.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}