{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T10:40:15Z","timestamp":1788345615469,"version":"build-2803163510"},"reference-count":68,"publisher":"Wiley","issue":"32","license":[{"start":{"date-parts":[[2007,9,28]],"date-time":"2007-09-28T00:00:00Z","timestamp":1190937600000},"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":[[2007,11,5]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Reaction of the aryl\u2010monophosphine ligand \u03b1<jats:sup>2<\/jats:sup>\u2010(diisopropylphosphino)isodurene (<jats:bold>1<\/jats:bold>) with the Rh<jats:sup>I<\/jats:sup> precursor [Rh(coe)<jats:sub>2<\/jats:sub>(acetone)<jats:sub>2<\/jats:sub>]BF<jats:sub>4<\/jats:sub> (coe=cyclooctene) in different solvents yielded complexes of all three common oxidation states of rhodium, depending on the solvent used. When the reaction was carried out in methanol a cyclometalated, solvent\u2010stabilized Rh<jats:sup>III<\/jats:sup> alkyl\u2010hydride complex (<jats:bold>2<\/jats:bold>) was obtained. However, when the reaction was carried out in acetone or dichloromethane a dinuclear \u03b7<jats:sup>6<\/jats:sup>\u2010arene Rh<jats:sup>II<\/jats:sup> complex (<jats:bold>5<\/jats:bold>) was obtained in the absence of added redox reagents. Moreover, when acetonitrile was added to a solution of either the Rh<jats:sup>II<\/jats:sup> or Rh<jats:sup>III<\/jats:sup> complexes, a new solvent\u2010stabilized, noncyclometalated Rh<jats:sup>I<\/jats:sup> complex (<jats:bold>6<\/jats:bold>) was obtained. In this report we describe the different complexes, which were fully characterized, and probe the processes behind the remarkable solvent effect observed.<\/jats:p>","DOI":"10.1002\/chem.200700805","type":"journal-article","created":{"date-parts":[[2007,9,28]],"date-time":"2007-09-28T11:46:38Z","timestamp":1190979998000},"page":"9043-9055","source":"Crossref","is-referenced-by-count":20,"title":["Solvent\u2010Dependent Interconversions between Rh<sup>I<\/sup>, Rh<sup>II<\/sup>, and Rh<sup>III<\/sup> Complexes of an Aryl\u2013Monophosphine Ligand"],"prefix":"10.1002","volume":"13","author":[{"given":"Michael","family":"Montag","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregory","family":"Leitus","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linda\u2005J.\u2005W.","family":"Shimon","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yehoshoa","family":"Ben\u2010David","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Milstein","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2007,10,24]]},"reference":[{"key":"e_1_2_6_1_2","unstructured":"For general reviews of rhodium(II) complexes see:"},{"key":"e_1_2_6_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/9780470166307.ch2"},{"key":"e_1_2_6_3_2","doi-asserted-by":"publisher","DOI":"10.1016\/0010-8545(94)01127-3"},{"key":"e_1_2_6_4_2","doi-asserted-by":"publisher","DOI":"10.1007\/0-387-25829-9_12"},{"key":"e_1_2_6_5_2","unstructured":"For reviews of catalytic applications involving dirhodium(II) complexes see:"},{"key":"e_1_2_6_6_2","doi-asserted-by":"publisher","DOI":"10.1007\/b98766"},{"key":"e_1_2_6_7_2","doi-asserted-by":"publisher","DOI":"10.1007\/0-387-25829-9_13"},{"key":"e_1_2_6_8_2","unstructured":"For example alcohols (e.g. methanol ethanol) are used as mild reductants in the synthesis of RhIIcarboxylates. Silver salts are also commonly used."},{"key":"e_1_2_6_9_2","doi-asserted-by":"publisher","DOI":"10.1039\/b110183h"},{"key":"e_1_2_6_10_2","unstructured":"For examples see the following:"},{"key":"e_1_2_6_11_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00424a069"},{"key":"e_1_2_6_12_2","doi-asserted-by":"publisher","DOI":"10.1039\/b212027e"},{"key":"e_1_2_6_13_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200401334"},{"key":"e_1_2_6_14_2","doi-asserted-by":"publisher","DOI":"10.1039\/b617295d"},{"key":"e_1_2_6_15_2","unstructured":"\u00a0"},{"key":"e_1_2_6_16_2","doi-asserted-by":"publisher","DOI":"10.1021\/om9600452"},{"key":"e_1_2_6_17_2","doi-asserted-by":"publisher","DOI":"10.1021\/om9802818"},{"key":"e_1_2_6_18_2","unstructured":"Ligands of this type have also been described by Werner and co\u2010workers. For examples see:"},{"key":"e_1_2_6_19_2","doi-asserted-by":"publisher","DOI":"10.1039\/b310190h"},{"key":"e_1_2_6_20_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200204623"},{"key":"e_1_2_6_21_2","doi-asserted-by":"publisher","DOI":"10.1021\/om034348p"},{"key":"e_1_2_6_22_2","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3765(20000901)6:17<3287::AID-CHEM3287>3.0.CO;2-J"},{"key":"e_1_2_6_23_2","unstructured":"Determination of the number of coordinated solvent molecules requires the removal of excess solvent. This can be accomplished by precipitation and\/or removal of the solvent under vacuum. Unfortunately attempts to isolate pure samples of2\u2009aby these methods were unsuccessful due to the instability of the complex in the absence of a stabilizing solvent (see the main text for further discussion)."},{"key":"e_1_2_6_24_2","unstructured":"It was shown by NMR and IR spectroscopies as well as X\u2010ray crystallography that complex4\u2009bcontains three solvent molecules (see ref.\u2005[8]). This conclusion may also be applied to4\u2009a because methanol is both smaller in size (less steric hindrance) and more strongly\u2010coordinating than acetone. We may then further extend this conclusion to2\u2009a because the metal center in this complex is less sterically hindered than in4\u2009a(ligand1is less bulky than3)."},{"key":"e_1_2_6_25_2","unstructured":"Complex4may also undergo dimerization as was observed for similar systems (unpublished results) but such a process has not been reported thus far."},{"key":"e_1_2_6_26_2","unstructured":"To the best of our knowledge this is the only case reported thus far of a dinuclear RhIIcomplex with an \u03b76\u2010bound benzenoid ligand. For examples of dinuclear RhIIcomplexes with benzenoid ligands in other binding modes see:"},{"key":"e_1_2_6_27_2","doi-asserted-by":"publisher","DOI":"10.1021\/om9901933"},{"key":"e_1_2_6_28_2","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3765(20020402)8:7<1591::AID-CHEM1591>3.0.CO;2-0"},{"key":"e_1_2_6_29_2","doi-asserted-by":"publisher","DOI":"10.1021\/om051100m"},{"key":"e_1_2_6_30_2","unstructured":"The hydride ligand was explicitly located in the electron density map."},{"key":"e_1_2_6_31_2","unstructured":"For surveys of Rh\uf8ffRh bond lengths see:"},{"key":"e_1_2_6_32_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic00093a035"},{"key":"e_1_2_6_33_2","unstructured":"ref.\u2005[1\u2009c]."},{"key":"e_1_2_6_34_2","doi-asserted-by":"publisher","DOI":"10.1002\/mrc.1439"},{"key":"e_1_2_6_35_2","unstructured":"\u00a0"},{"key":"e_1_2_6_36_2","doi-asserted-by":"publisher","DOI":"10.1021\/om020248s"},{"key":"e_1_2_6_37_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic0204981"},{"key":"e_1_2_6_38_2","unstructured":"To the best of our knowledge no crystal structure of analogous RhII\u2010benzyl complexes has been reported elsewhere."},{"key":"e_1_2_6_39_2","unstructured":"The reported initial concentration of complex2was obtained by reacting [Rh(coe)2(acetone)2]BF4and ligand1 each at 80\u2005mMconcentration (after mixing). The relatively low concentration of2obtained in this reaction is due to the formation of other products as described in the main text."},{"key":"e_1_2_6_40_2","unstructured":"The concentration of complexes was estimated on the basis of31P{1H} NMR spectra and the initial concentration of precursors ([Rh(coe)2(acetone)2]BF4and ligand1)."},{"key":"e_1_2_6_41_2","unstructured":"The amount of minor product decreased even further as the system approached equilibrium at room temperature. See the main text for further information."},{"key":"e_1_2_6_42_2","unstructured":"As suggested in our previous publication (ref.\u2005[8]) the chemical exchange observed by SST is due to rapid C\uf8ffH reductive elimination without complete detachment of the arene moiety from the metal center (a process which involves agostic intermediates)."},{"key":"e_1_2_6_43_2","unstructured":"The fact that addition of acetonitrile to complex5leads to a product ratio of2\u2009c:6\u2009a\u22481:1 can be rationalized on the basis of the structure of complex5(Figure\u20051a). This is essentially made up of one unit of complex2and one unit of complex6(without the solvent molecules) and hence the solvent\u2010promoted breakup of complex5should first lead to an equimolar mixture of2\u2009cand6\u2009a."},{"key":"e_1_2_6_44_2","unstructured":"We have previously shown that in complex4the bridging methylene protons are also involved in the exchange. For further details see ref.\u2005[8]."},{"key":"e_1_2_6_45_2","unstructured":"Similar observations were previously reported by our group for complex4 see ref.\u2005[8]."},{"key":"e_1_2_6_46_2","unstructured":"\u00a0"},{"key":"e_1_2_6_47_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00383a039"},{"key":"e_1_2_6_48_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar00102a004"},{"key":"e_1_2_6_49_2","unstructured":"Complex8was found to exhibit fluxional behavior in solution at room temperature. Therefore characterization of this complex by NMR spectroscopy was done both at room temperature and \u221220\u2009\u00b0C (see Experimental Section). The fluxionality of complex8and related issues will be discussed elsewhere."},{"key":"e_1_2_6_50_2","unstructured":"The mechanism of this reaction is unclear but it is unlikely to involve predissociation of ligand1from8 since this complex was found to be stable in acetone even at elevated temperatures (e.g. 90\u2005min at 60\u2009\u00b0C) with no free ligand being observed. Further observations related to complex8will be reported elsewhere."},{"key":"e_1_2_6_51_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja029197g"},{"key":"e_1_2_6_52_2","unstructured":"Bimetallic RhI\/RhIIImixed\u2010valence complexes have been reported both as labile intermediates and as stable species. For examples see:"},{"key":"e_1_2_6_53_2","doi-asserted-by":"publisher","DOI":"10.1039\/dt9860000015"},{"key":"e_1_2_6_54_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00102a023"},{"key":"e_1_2_6_55_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1099-0682(199808)1998:8<1187::AID-EJIC1187>3.0.CO;2-Y"},{"key":"e_1_2_6_56_2","doi-asserted-by":"publisher","DOI":"10.1021\/om000946h"},{"key":"e_1_2_6_57_2","unstructured":"\u03b76\u2010arene complexes of both RhIand RhIIIare known. For examples see:"},{"key":"e_1_2_6_58_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic50215a053"},{"key":"e_1_2_6_59_2","unstructured":"ref.\u2005[7\u2009c];"},{"key":"e_1_2_6_60_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11172-005-0054-5"},{"key":"e_1_2_6_61_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja062110x"},{"key":"e_1_2_6_62_2","unstructured":"Such an inner\u2010sphere process is expected to be highly efficient and also preserve the electronic saturation of the two rhodium centers."},{"key":"e_1_2_6_63_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-328X(85)87262-4"},{"key":"e_1_2_6_64_2","doi-asserted-by":"publisher","DOI":"10.1021\/om960114c"},{"key":"e_1_2_6_65_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1099-0682(199904)1999:4<613::AID-EJIC613>3.0.CO;2-L"},{"key":"e_1_2_6_66_2","unstructured":"S.\u2010Y. Liou PhD Thesis Weizmann Institute of Science (Rehovot Israel) 1995."},{"key":"e_1_2_6_67_2","doi-asserted-by":"publisher","DOI":"10.1021\/jo00057a046"},{"key":"e_1_2_6_68_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.19970030214"}],"container-title":["Chemistry \u2013 A European Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchem.200700805","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chem.200700805","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T11:02:55Z","timestamp":1760266975000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/chem.200700805"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,10,24]]},"references-count":68,"journal-issue":{"issue":"32","published-print":{"date-parts":[[2007,11,5]]}},"alternative-id":["10.1002\/chem.200700805"],"URL":"https:\/\/doi.org\/10.1002\/chem.200700805","archive":["Portico"],"relation":{},"ISSN":["0947-6539","1521-3765"],"issn-type":[{"value":"0947-6539","type":"print"},{"value":"1521-3765","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,10,24]]}}}