{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T19:28:45Z","timestamp":1791142125812,"version":"4.1.0"},"reference-count":96,"publisher":"Wiley","issue":"31","license":[{"start":{"date-parts":[[2014,6,25]],"date-time":"2014-06-25T00:00:00Z","timestamp":1403654400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemistry A European J"],"published-print":{"date-parts":[[2014,7,28]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>A reaction of a 2\u2010(imidazol\u20101\u2010yl)methyl\u20106\u2010(pyrazol\u20103\u2010yl)pyridine with [RuCl<jats:sub>2<\/jats:sub>(PPh<jats:sub>3<\/jats:sub>)<jats:sub>3<\/jats:sub>] resulted in tautomerization of the imidazole unit to afford the unsymmetrical pincer\u2010type ruthenium complex <jats:bold>2<\/jats:bold> containing a protic pyrazole and N\u2010heterocyclic carbene (NHC) arms. Deprotonation of <jats:bold>2<\/jats:bold> with one equivalent of a base led to the formation of the NHC\u2013pyrazolato complex <jats:bold>3<\/jats:bold>, indicating that the protic NHC arm is less acidic. When <jats:bold>2<\/jats:bold> was treated with two equivalents of a base under H<jats:sub>2<\/jats:sub> or in 2\u2010propanol, the hydrido complex <jats:bold>4<\/jats:bold> containing protic NHC and pyrazolato groups was obtained through metal\u2013ligand cooperation.<\/jats:p>","DOI":"10.1002\/chem.201403179","type":"journal-article","created":{"date-parts":[[2014,6,25]],"date-time":"2014-06-25T11:58:26Z","timestamp":1403697506000},"page":"9539-9542","source":"Crossref","is-referenced-by-count":45,"title":["Unsymmetrical Pincer\u2010Type Ruthenium Complex Containing \u03b2\u2010Protic Pyrazole and N\u2010Heterocyclic Carbene Arms: Comparison of Br\u00f8nsted Acidity of NH Groups in Second Coordination Sphere"],"prefix":"10.1002","volume":"20","author":[{"given":"Tatsuro","family":"Toda","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shigeki","family":"Kuwata","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takao","family":"Ikariya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2014,6,25]]},"reference":[{"key":"e_1_2_4_1_2","unstructured":"\u00a0"},{"key":"e_1_2_4_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201204100"},{"key":"e_1_2_4_2_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201204100"},{"key":"e_1_2_4_3_2","doi-asserted-by":"publisher","DOI":"10.1039\/C2NJ40659D"},{"key":"e_1_2_4_4_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs3005083"},{"key":"e_1_2_4_5_2","doi-asserted-by":"publisher","DOI":"10.1002\/cctc.201100347"},{"key":"e_1_2_4_6_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejic.201100880"},{"key":"e_1_2_4_7_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejic.201100752"},{"key":"e_1_2_4_8_2","doi-asserted-by":"publisher","DOI":"10.1246\/cl.2010.908"},{"key":"e_1_2_4_9_2","unstructured":"\u00a0"},{"key":"e_1_2_4_10_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201204921"},{"key":"e_1_2_4_10_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201204921"},{"key":"e_1_2_4_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs300341g"},{"key":"e_1_2_4_12_2","doi-asserted-by":"publisher","DOI":"10.1246\/bcsj.20100249"},{"key":"e_1_2_4_13_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.201003296"},{"key":"e_1_2_4_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/asia.201200014"},{"key":"e_1_2_4_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja3122944"},{"key":"e_1_2_4_16_2","unstructured":"\u00a0"},{"key":"e_1_2_4_17_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200902827"},{"key":"e_1_2_4_18_2","doi-asserted-by":"publisher","DOI":"10.1246\/bcsj.20100331"},{"key":"e_1_2_4_19_2","doi-asserted-by":"publisher","DOI":"10.1021\/om301063n"},{"key":"e_1_2_4_20_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ica.2013.12.041"},{"key":"e_1_2_4_21_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejic.201000802"},{"key":"e_1_2_4_22_2","unstructured":"\u00a0"},{"key":"e_1_2_4_23_2","doi-asserted-by":"publisher","DOI":"10.1039\/c3dt51580j"},{"key":"e_1_2_4_24_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.201103374"},{"key":"e_1_2_4_25_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic200547k"},{"key":"e_1_2_4_26_2","doi-asserted-by":"publisher","DOI":"10.1021\/om9004753"},{"key":"e_1_2_4_27_2","unstructured":"\u00a0"},{"key":"e_1_2_4_28_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja412449v"},{"key":"e_1_2_4_29_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja411438d"},{"key":"e_1_2_4_30_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.molcata.2013.10.019"},{"key":"e_1_2_4_31_2","doi-asserted-by":"publisher","DOI":"10.1021\/cs400834q"},{"key":"e_1_2_4_32_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic401667v"},{"key":"e_1_2_4_33_2","doi-asserted-by":"publisher","DOI":"10.1021\/om400445n"},{"key":"e_1_2_4_34_2","doi-asserted-by":"publisher","DOI":"10.1021\/om400298c"},{"key":"e_1_2_4_35_2","unstructured":"\u00a0"},{"key":"e_1_2_4_36_2","doi-asserted-by":"publisher","DOI":"10.1039\/C3DT51867A"},{"key":"e_1_2_4_37_2","doi-asserted-by":"publisher","DOI":"10.1002\/adsc.201200629"},{"key":"e_1_2_4_38_2","unstructured":"\u00a0"},{"key":"e_1_2_4_39_2","doi-asserted-by":"publisher","DOI":"10.1246\/cl.2010.758"},{"key":"e_1_2_4_40_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejic.201100800"},{"key":"e_1_2_4_41_2","unstructured":"\u00a0"},{"key":"e_1_2_4_42_2","doi-asserted-by":"publisher","DOI":"10.1039\/c3nj41146j"},{"key":"e_1_2_4_43_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja5001888"},{"key":"e_1_2_4_44_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic401707u"},{"key":"e_1_2_4_45_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic302448d"},{"key":"e_1_2_4_46_2","doi-asserted-by":"publisher","DOI":"10.1039\/C2CC36927C"},{"key":"e_1_2_4_47_2","unstructured":"\u00a0"},{"key":"e_1_2_4_48_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar2000265"},{"key":"e_1_2_4_49_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201311221"},{"key":"e_1_2_4_49_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201311221"},{"key":"e_1_2_4_50_2","doi-asserted-by":"publisher","DOI":"10.1021\/om401053j"},{"key":"e_1_2_4_51_2","doi-asserted-by":"publisher","DOI":"10.1038\/nchem.1595"},{"key":"e_1_2_4_52_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja310782k"},{"key":"e_1_2_4_53_2","doi-asserted-by":"publisher","DOI":"10.1039\/C2DT31907A"},{"key":"e_1_2_4_54_2","doi-asserted-by":"publisher","DOI":"10.1039\/c2dt31009k"},{"key":"e_1_2_4_55_2","doi-asserted-by":"publisher","DOI":"10.1021\/om2010172"},{"key":"e_1_2_4_56_2","volume-title":"Biological Inorganic Chemistry: Structure and Reactivity","author":"Bertini I.","year":"2007"},{"key":"e_1_2_4_57_2","unstructured":"\u00a0"},{"key":"e_1_2_4_58_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja403852e"},{"key":"e_1_2_4_59_2","doi-asserted-by":"publisher","DOI":"10.1246\/bcsj.20120359"},{"key":"e_1_2_4_60_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja3097674"},{"key":"e_1_2_4_61_2","doi-asserted-by":"publisher","DOI":"10.1021\/om800285n"},{"key":"e_1_2_4_62_2","doi-asserted-by":"publisher","DOI":"10.1002\/cctc.201200567"},{"key":"e_1_2_4_63_2","unstructured":"\u00a0"},{"key":"e_1_2_4_64_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja804713u"},{"key":"e_1_2_4_65_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201005100"},{"key":"e_1_2_4_65_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201005100"},{"key":"e_1_2_4_66_2","doi-asserted-by":"publisher","DOI":"10.1021\/om101173e"},{"key":"e_1_2_4_67_2","unstructured":"\u00a0"},{"key":"e_1_2_4_68_2","doi-asserted-by":"publisher","DOI":"10.1039\/c3cc47987k"},{"key":"e_1_2_4_69_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201308269"},{"key":"e_1_2_4_69_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201308269"},{"key":"e_1_2_4_70_2","doi-asserted-by":"publisher","DOI":"10.1039\/c3cs60019j"},{"key":"e_1_2_4_71_2","doi-asserted-by":"publisher","DOI":"10.1039\/C2DT11974A"},{"key":"e_1_2_4_72_2","doi-asserted-by":"publisher","DOI":"10.1021\/om100841j"},{"key":"e_1_2_4_73_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.201000459"},{"key":"e_1_2_4_74_2","doi-asserted-by":"publisher","DOI":"10.1039\/b900955h"},{"key":"e_1_2_4_75_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja073144n"},{"key":"e_1_2_4_76_2","unstructured":"Hahn and co\u2010workers have recently proposed that such reactions take place via a redox tautomerization which involves oxidative addition of the C\uf8ffH bond at the 2\u2010position and subsequent reductive elimination of the resulting hydride:[18]"},{"key":"e_1_2_4_77_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.201202973"},{"key":"e_1_2_4_78_2","doi-asserted-by":"publisher","DOI":"10.1021\/om200689r"},{"key":"e_1_2_4_79_2","doi-asserted-by":"publisher","DOI":"10.1021\/om100388w"},{"key":"e_1_2_4_80_2","unstructured":"Crystal data for2\u22c5CH3OH: C57H61ClF6N5OP3Ru Mr=1175.58 crystal dimensions 0.30\u00d70.22\u00d70.13\u2005mm monoclinic P21\/n a=12.815(6) b=26.318(11) c=16.226(7)\u2005\u00c5 \u03b2=92.416(6)\u00b0 V=5467(4)\u2005\u00c53 Z=4 \u03c1calcd=1.428\u2005g\u2009cm\u22123 \u03bc=0.489\u2005mm\u22121 F000=2424 transmission factors 0.799\u20130.938 reflection measured 60835 independent reflections 12293 no. of valuables 731 Rint=0.0836 R1=0.0477 [I>2\u03c3(I)] wR2=0.1264 (all data) residual electron density 1.32\/\u22121.04\u2005e\u2009\u00c53. For3\u22c50.5CH2Cl2: C56.5H57Cl2N5P2Ru Mr=1040.03 crystal dimensions 0.15\u00d70.10\u00d70.08\u2005mm monoclinic P21\/n a=19.248(5) b=22.739(6) c=23.947(6)\u2005\u00c5 \u03b2=90.993(3)\u00b0 V=10480(5)\u2005\u00c53 Z=8 \u03c1calcd=1.318\u2005g\u2009cm\u22123 \u03bc=0.504\u2005mm\u22121 F000=4312 transmission factors 0.865\u20130.961 reflection measured 116752 independent reflections 23951 no. of valuables 1309 Rint=0.0687 R1=0.0696 [I>2\u03c3(I)] wR2=0.1713 (all data) residual electron density 2.26\/\u22122.27\u2005e\u2009\u00c5\u22123. Data was collected at 93\u2005K with graphite\u2010monochromated MoK\u03b1radiation (\u03bb=0.7107\u2005\u00c5) to a maximum 2\u03b8value of 55\u00b0. Intensity data were corrected for Lorentz polarization effects and for absorption. Structure solution and refinements were performed with the CrystalStructure program package.[24]The structures were refined againstF2. The hydroxy hydrogen atom in the solvating methanol in2\u22c5CH3OH was isotropically refined whereas the rest hydrogen atoms except for those in the disordered components were included in the refinements by using a riding model."},{"key":"e_1_2_4_81_2","unstructured":"CrystalStructure 4.0 Crystal Structure Analysis Package Rigaku Corporation Tokyo 196\u20138666 Japan 2000\u20132010."},{"key":"e_1_2_4_82_2","unstructured":"Complex2can also be deprotonated with triethylamine (pKaof BH+=9.00 in DMSO) in CD2Cl2 whereas2seems inert toward 2 6\u2010lutidine (4.46). A1H\u2005NMR experiment revealed that the bis(pyrazole)complex1protonates the NHC\u2013pyrazolato complex3 indicating the Br\u00f8nsted acidity of1superior to that of2."},{"key":"e_1_2_4_83_2","unstructured":"The pKavalues of [RuL(NH3)5]3+(L=a protic NHC and pyrazole) are reported to be 11.0 and 5.98 respectively:"},{"key":"e_1_2_4_84_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic00139a020"},{"key":"e_1_2_4_85_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic00186a009"},{"key":"e_1_2_4_86_2","unstructured":"Preliminary deprotonation experiments of2with two\u2005equivalents of KOtBu in toluene under nitrogen led to the formation of a dinitrogen adduct5\u2013N2 which was characterized by the$\\tilde \\nu $(NN) band (2156\u2005cm\u22121) in the IR spectrum."},{"key":"e_1_2_4_87_2","unstructured":"For heterolytic cleavage of dihydrogen by metal\u2013ligand cooperation see:"},{"key":"e_1_2_4_88_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jorganchem.2013.07.041"},{"key":"e_1_2_4_89_2","doi-asserted-by":"publisher","DOI":"10.1039\/C0NJ00776E"},{"key":"e_1_2_4_90_2","doi-asserted-by":"publisher","DOI":"10.1021\/om100436c"},{"key":"e_1_2_4_91_2","doi-asserted-by":"publisher","DOI":"10.1021\/om8006213"}],"container-title":["Chemistry \u2013 A European Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchem.201403179","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chem.201403179","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T15:25:38Z","timestamp":1760282738000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/chem.201403179"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,6,25]]},"references-count":96,"journal-issue":{"issue":"31","published-print":{"date-parts":[[2014,7,28]]}},"alternative-id":["10.1002\/chem.201403179"],"URL":"https:\/\/doi.org\/10.1002\/chem.201403179","archive":["Portico"],"relation":{},"ISSN":["0947-6539","1521-3765"],"issn-type":[{"value":"0947-6539","type":"print"},{"value":"1521-3765","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,6,25]]}}}