{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T06:11:50Z","timestamp":1777961510712,"version":"3.51.4"},"reference-count":106,"publisher":"Wiley","issue":"48","license":[{"start":{"date-parts":[[2011,10,31]],"date-time":"2011-10-31T00:00:00Z","timestamp":1320019200000},"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":[[2011,11,25]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>An efficient method for the synthesis of the first N\u2010heterocyclic carbene (NHC)\u2010stabilized halosilylidyne complexes is reported that starts from SiBr<jats:sub>4<\/jats:sub>. In the first step, SiBr<jats:sub>4<\/jats:sub> was treated with one equivalent of the N\u2010heterocyclic carbene 1,3\u2010bis[2,6\u2010bis(isopropyl)phenyl]imidazolidin\u20102\u2010ylidene (SIdipp) to give the 4,5\u2010dihydroimidazolium salt [SiBr<jats:sub>3<\/jats:sub>(SIdipp)]Br (<jats:bold>1\u2010Br<\/jats:bold>), which then was reduced with potassium graphite to afford the silicon(II) dibromide\u2013NHC adduct SiBr<jats:sub>2<\/jats:sub>(SIdipp) (<jats:bold>2\u2010Br<\/jats:bold>) in good yields. Heating <jats:bold>2\u2010Br<\/jats:bold> with Li[CpCr(CO)<jats:sub>3<\/jats:sub>] afforded the complex [Cp(CO)<jats:sub>2<\/jats:sub>Cr\uf8feSiBr(SIdipp)] (<jats:bold>3\u2010Br<\/jats:bold>) upon elimination of CO. Complex <jats:bold>3\u2010Br<\/jats:bold> features a trigonal\u2010planar\u2010coordinated silicon center and a very short Cr\uf8feSi double bond. Similarly, the reaction of SiCl<jats:sub>2<\/jats:sub>(SIdipp) (<jats:bold>2\u2010Cl<\/jats:bold>) with Li[CpCr(CO)<jats:sub>3<\/jats:sub>] gave the analogous chloro derivative [Cp(CO)<jats:sub>2<\/jats:sub>Cr\uf8feSiCl(SIdipp)] (<jats:bold>3\u2010Cl<\/jats:bold>). Complex <jats:bold>3\u2010Br<\/jats:bold> undergoes an NHC exchange with 1,3\u2010dihydro\u20104,5\u2010dimethyl\u20101,3\u2010bis(isopropyl)\u20102<jats:italic>H<\/jats:italic>\u2010imidazol\u20102\u2010ylidene (IMe<jats:sub>2<\/jats:sub><jats:italic>i<\/jats:italic>Pr<jats:sub>2<\/jats:sub>) to give the complex [Cp(CO)<jats:sub>2<\/jats:sub>CrSiBr(IMe<jats:sub>2<\/jats:sub><jats:italic>i<\/jats:italic>Pr<jats:sub>2<\/jats:sub>)<jats:sub>2<\/jats:sub>] (<jats:bold>4\u2010Br<\/jats:bold>). Compound <jats:bold>4\u2010Br<\/jats:bold> features a distorted\u2010tetrahedral four\u2010coordinate silicon center. Bromide abstraction occurs readily from <jats:bold>4\u2010Br<\/jats:bold> with Li[B(C<jats:sub>6<\/jats:sub>F<jats:sub>5<\/jats:sub>)<jats:sub>4<\/jats:sub>] to give the putative silylidene complex salt [Cp(CO)<jats:sub>2<\/jats:sub>Cr\uf8feSi(IMe<jats:sub>2<\/jats:sub><jats:italic>i<\/jats:italic>Pr<jats:sub>2<\/jats:sub>)<jats:sub>2<\/jats:sub>][B(C<jats:sub>6<\/jats:sub>F<jats:sub>5<\/jats:sub>)<jats:sub>4<\/jats:sub>], which irreversibly dimerizes by means of an Si\u2010promoted electrophilic activation of one carbonyl oxygen atom to yield the dinuclear siloxycarbyne complex [Cp(CO)Cr{(\u03bc\u2010CO)Si(IMe<jats:sub>2<\/jats:sub><jats:italic>i<\/jats:italic>Pr<jats:sub>2<\/jats:sub>)<jats:sub>2<\/jats:sub>}<jats:sub>2<\/jats:sub>\u2010 Cr(CO)Cp][B(C<jats:sub>6<\/jats:sub>F<jats:sub>5<\/jats:sub>)<jats:sub>4<\/jats:sub>]<jats:sub>2<\/jats:sub> (<jats:bold>5<\/jats:bold>). All compounds were fully characterized, and the molecular structures of <jats:bold>2\u2010Br<\/jats:bold>\u2013<jats:bold>5\u2010Br<\/jats:bold> were determined by single\u2010crystal X\u2010ray diffraction. DFT calculations of <jats:bold>3\u2010Br<\/jats:bold> and <jats:bold>3\u2010Cl<\/jats:bold> and their carbene dissociation products [Cp(CO)<jats:sub>2<\/jats:sub>Cr\uf8fdSi\uf8ffX] (X=Cl, Br) were carried out, and the electronic structures of <jats:bold>3\u2010Br<\/jats:bold>, <jats:bold>3\u2010Cl<\/jats:bold> and [Cp(CO)<jats:sub>2<\/jats:sub>Cr\uf8fdSi\uf8ffX] were analyzed by the natural bond orbital method in combination with natural resonance theory.<\/jats:p>","DOI":"10.1002\/chem.201102659","type":"journal-article","created":{"date-parts":[[2011,10,31]],"date-time":"2011-10-31T05:37:38Z","timestamp":1320039458000},"page":"13574-13583","source":"Crossref","is-referenced-by-count":82,"title":["Chromium\uf8ffSilicon Multiple Bonds: The Chemistry of Terminal N\u2010Heterocyclic\u2010Carbene\u2010Stabilized Halosilylidyne Ligands"],"prefix":"10.1002","volume":"17","author":[{"given":"Alexander C.","family":"Filippou","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Oleg","family":"Chernov","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gregor","family":"Schnakenburg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2011,10,31]]},"reference":[{"key":"e_1_2_5_1_2","unstructured":"\u00a0"},{"key":"e_1_2_5_2_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.104715"},{"key":"e_1_2_5_3_2","volume-title":"Principles of Plasma Discharges and Material Processing","author":"Liebermann M. A.","year":"1994"},{"key":"e_1_2_5_4_2","doi-asserted-by":"publisher","DOI":"10.1116\/1.1612932"},{"key":"e_1_2_5_5_2","doi-asserted-by":"publisher","DOI":"10.1088\/0022-3727\/37\/14\/010"},{"key":"e_1_2_5_6_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.1786338"},{"key":"e_1_2_5_7_2","unstructured":"\u00a0"},{"key":"e_1_2_5_8_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.339548"},{"key":"e_1_2_5_9_2","doi-asserted-by":"publisher","DOI":"10.1143\/JJAP.32.3089"},{"key":"e_1_2_5_10_2","doi-asserted-by":"publisher","DOI":"10.1088\/0022-3727\/39\/14\/023"},{"key":"e_1_2_5_11_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijms.2006.07.012"},{"key":"e_1_2_5_12_2","unstructured":"Selected references on the thermochemistry and structure of halosilylidynes:"},{"key":"e_1_2_5_13_2","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4757-0961-2"},{"key":"e_1_2_5_14_2","doi-asserted-by":"publisher","DOI":"10.1021\/ar00068a004"},{"key":"e_1_2_5_15_2","doi-asserted-by":"publisher","DOI":"10.1021\/jp022524m"},{"key":"e_1_2_5_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.molstruc.2005.04.050"},{"key":"e_1_2_5_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijms.2008.07.004"},{"key":"e_1_2_5_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.chemphys.2009.02.009"},{"key":"e_1_2_5_19_2","unstructured":"\u00a0"},{"key":"e_1_2_5_20_2","doi-asserted-by":"publisher","DOI":"10.1039\/c39840000075"},{"key":"e_1_2_5_21_2","doi-asserted-by":"publisher","DOI":"10.1039\/C39880001606"},{"key":"e_1_2_5_22_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00006a073"},{"key":"e_1_2_5_23_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja960940c"},{"key":"e_1_2_5_24_2","doi-asserted-by":"publisher","DOI":"10.1021\/om990114n"},{"key":"e_1_2_5_25_2","doi-asserted-by":"publisher","DOI":"10.1021\/om100896r"},{"key":"e_1_2_5_26_2","unstructured":"\u00a0"},{"key":"e_1_2_5_27_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200901766"},{"key":"e_1_2_5_27_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200901766"},{"key":"e_1_2_5_28_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200902431"},{"key":"e_1_2_5_28_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200902431"},{"key":"e_1_2_5_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0040-4020(99)00927-8"},{"key":"e_1_2_5_30_2","unstructured":"Two independent molecules of2\u2010Brwith very similar geometric parameters were found in the asymmetric unit. The unweighted mean valuesxuof the individual bonding parameters of the two molecules were used in the discussion of the structure of2\u2010Br. The standard deviations\u03c3ofxu(values in parentheses) were calculated using the equation\u03c32=\u03a3(x\u03b9\u2212xu)2\/(n2\u2212n) in whichxiis the respective individual value andnis the total number of individual values."},{"key":"e_1_2_5_31_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200903019"},{"key":"e_1_2_5_32_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00347a061"},{"key":"e_1_2_5_33_2","unstructured":"A CSD survey (2.7.2011) revealed that only 23 complexes with Cr\uf8ffSi bonds have been structurally characterized to date which leads to a median and mean Cr\uf8ffSi distance of 2.382 and 2.402\u2005\u00c5 respectively. The shortest Cr\uf8ffSi bond length has been found to be 2.326\u2005\u00c5 and the longest 2.6603(8)\u2005\u00c5:"},{"key":"e_1_2_5_34_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-328X(01)00765-3"},{"key":"e_1_2_5_35_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja803798b"},{"key":"e_1_2_5_36_2","unstructured":"Only two chromium silylidene complexes that contain a trigonal\u2010planar\u2010coordinated silicon center have been structurally characterized.[10a]All other chromium silylidene complexes are of the general formula [(CO)5Cr(SiR2B)] and contain an intra\u2010 or intermolecular base\u2010stabilized distorted tetrahedral\u2010coordinated silicon center:"},{"key":"e_1_2_5_37_2","doi-asserted-by":"publisher","DOI":"10.1021\/om00096a022"},{"key":"e_1_2_5_38_2","doi-asserted-by":"publisher","DOI":"10.1021\/om00038a004"},{"key":"e_1_2_5_39_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-328X(93)86067-R"},{"key":"e_1_2_5_40_2","doi-asserted-by":"publisher","DOI":"10.1021\/om00030a028"},{"key":"e_1_2_5_41_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.19931050918"},{"key":"e_1_2_5_41_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.199313131"},{"key":"e_1_2_5_42_2","doi-asserted-by":"publisher","DOI":"10.1039\/cc9960001299"},{"key":"e_1_2_5_43_2","doi-asserted-by":"publisher","DOI":"10.1021\/om980032j"},{"key":"e_1_2_5_44_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200901472"},{"key":"e_1_2_5_45_2","unstructured":"The upright conformation is best demonstrated by the dihedral angle of 20.8\u00b0 (3\u2010Br) and 21.4\u00b0 (3\u2010Cl) between the plane of the NHC\u2010stabilized silylidyne ligand that passes through the atoms Si X (X=Cl Br) and Ccarbene and the plane defined by the atoms Si Cr and Cg for which Cgdenotes the center of gravity of the cyclopentadienyl ring."},{"key":"e_1_2_5_46_2","unstructured":"The term electron\u2010rich is used herein to emphasize the strong \u03c0\u2010electron\u2010donating ability of the chromium center in3\u2010Brand3\u2010Cl:"},{"key":"e_1_2_5_47_2","doi-asserted-by":"publisher","DOI":"10.1016\/0010-8545(90)80039-V"},{"key":"e_1_2_5_48_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0010-8545(01)00357-5"},{"key":"e_1_2_5_49_2","unstructured":"The unweighted mean valuexuof the Cr\uf8ffCO bond lengths is given respectively. The standard deviation\u03c3ofxu(value in parentheses) was calculated by using the equation given in reference\u2005[7]."},{"key":"e_1_2_5_50_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00441a005"},{"key":"e_1_2_5_51_2","unstructured":"The Supporting Information contains the crystal and structure refinement data of2 3\u2010Br\u22c50.5\u2009(hexane) 3\u2010Cl\u22c50.5\u2009(hexane) 4\u2010Br\u22c5C6H6 and5\u22c5C6H5F; illustrations of the calculated structures of3\u2010Br 3\u2010Cl and [Cp(CO)2Cr\uf8fdSi\uf8ffX] (X=Cl Br); and the cartesian atomic coordinates of all calculated minimum structures."},{"key":"e_1_2_5_52_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.201000837"},{"key":"e_1_2_5_52_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.201000837"},{"key":"e_1_2_5_53_2","unstructured":"A.\u2005C. Filippou O. Chernov G. Schnakenburg personal communication."},{"key":"e_1_2_5_54_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200800987"},{"key":"e_1_2_5_55_2","unstructured":"According to a CSD survey the median and mean value of the Cr\uf8ffSi single bond lengths of chromium silyl or silane complexes is 2.378 and 2.399\u2005\u00c5 respectively:"},{"key":"e_1_2_5_56_2","doi-asserted-by":"publisher","DOI":"10.1021\/om00039a008"},{"key":"e_1_2_5_57_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic00105a044"},{"key":"e_1_2_5_58_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja9714292"},{"key":"e_1_2_5_59_2","doi-asserted-by":"publisher","DOI":"10.1021\/om990201f"},{"key":"e_1_2_5_60_2","unstructured":"The mean Si\uf8ffBr bond length of all structurally characterized metal bromosilyl complexes and bromosilanes that feature a four\u2010coordinate silicon center is given. The Si\uf8ffBr bond lengths of the bromosilyl complexes range from 2.281 to 2.378\u2005\u00c5 and of the bromosilanes from 2.153 to 2.326\u2005\u00c5."},{"key":"e_1_2_5_61_2","unstructured":"An alternative view of the 18VE complex [Cp(CO)2Cr\uf8feSi(IMe2iPr2)2]+is that of na IMe2iPr2adduct of the cationic 18VE silylidyne complex [Cp(CO)2Cr\uf8fdSi(IMe2iPr2)]+or a bis\u2010IMe2iPr2adduct of the cationic complex [Cp(CO)2CrSi]+that features an end\u2010on bonded Si atom. Attempts to isolate such elusive species are currently underway."},{"key":"e_1_2_5_62_2","unstructured":"Only a few siloxycarbyne complexes (mostly of V\u2013Nb) have been reported to date:"},{"key":"e_1_2_5_63_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00216a062"},{"key":"e_1_2_5_64_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00017a030"},{"key":"e_1_2_5_65_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00055a074"},{"key":"e_1_2_5_66_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja050441o"},{"key":"e_1_2_5_67_2","unstructured":"\u00a0"},{"key":"e_1_2_5_68_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-328X(97)00084-3"},{"key":"e_1_2_5_69_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.19961080827"},{"key":"e_1_2_5_69_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.199608761"},{"key":"e_1_2_5_70_2","doi-asserted-by":"publisher","DOI":"10.1002\/ejoc.200700617"},{"key":"e_1_2_5_71_2","unstructured":"The mean Si\uf8ffO bond length of alkoxysilanes is 1.642\u2005\u00c5 according to a CSD survey (2.7.2011)."},{"key":"e_1_2_5_72_2","doi-asserted-by":"publisher","DOI":"10.1021\/om800179t"},{"key":"e_1_2_5_73_2","unstructured":"1H\u2005NMR spectrum of CH2\uf8feCH\uf8ffN(dipp)\uf8ffCH\uf8feN\uf8ffdipp (300.1\u2005MHz C6D6 298\u2005K):\u03b4=1.14 (br\u2009d 3J(H H)=6.8\u2005Hz 6\u2009H; 2\u00d7CHMeAMeB dipp) 1.19 (d 3J(H H)=6.8\u2005Hz 6\u2009H; 2\u00d7CHMeAMeB dipp) 1.24 (d 3J(H H)=6.8\u2005Hz 12\u2009H; 2\u00d7CHMe2 dipp) 3.18 (sept 3J(H H)=6.8\u2005Hz 2\u2009H; 2\u00d7CHMe2 dipp) 3.37 (br\u2009sept 3J(H H)=6.8\u2005Hz 2\u2009H; 2\u00d7CHMe2 dipp) 3.88 (br\u2009d 3J(H H)=15.5\u2005Hz 1\u2009H; CH\uf8feCHAHB) 4.18 (br\u2009s 1\u2009H; CH\uf8feCHAHB)* 7.06\u20137.22 (several multiplets 6\u2009H; 2\u00d7C6H3 dipp) 8.17\u2005ppm (br\u2009s 1\u2009H; NCHN). The signal marked with an asterisk was tentatively assigned and one CHsignal is probably hidden under the signals of the aromatic protons."},{"key":"e_1_2_5_74_2","unstructured":"NMR spectroscopic data of SIdipp are as follows:1H\u2005NMR (300.1\u2005MHz C6D6 298\u2005K):\u03b4=1.28 (d 3J(H H)=6.8\u2005Hz 12\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 1.33 (d 3J(H H)=6.8\u2005Hz 12\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 3.28 (sept 3J(H H)=6.9\u2005Hz 4\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 3.37 (s 4\u2009H; 2\u00d7NCH2) 7.16\u20137.20 (m 4\u2009H; 2\u00d7C3 \u20095\u2010H dipp) 7.24\u20137.29 (m 2\u2009H; 2\u00d7C4\u2010H dipp).13C{1H} NMR (75.47\u2005MHz C6D6 298\u2005K ppm):\u03b4=23.6 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 25.4 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 28.9 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 53.7 (s 4\u2009C; 2\u00d7NCH2) 124.0 (s 4\u2009C; 2\u00d7C3 \u20095\u2010H dipp) 128.3* (s 2\u2009C; 2\u00d7C4\u2010H dipp) 139.4 (s 2\u2009C; 2\u00d7C1 dipp) 147.4* (s 4\u2009C; 2\u00d7C2 \u20096 dipp) 244.1\u2005ppm (s 1\u2009C; NCN). The signals marked with an asterisk were incorrectly assigned in reference\u2005[6]."},{"key":"e_1_2_5_75_2","unstructured":"The CA index name of (SIdippH)Br is 1 3\u2010bis[2 6\u2010bis(1\u2010methylethyl)phenyl]\u20104 5\u2010dihydro\u20101H\u2010imidazolium bromide."},{"key":"e_1_2_5_76_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jorganchem.2009.03.014"},{"key":"e_1_2_5_77_2","unstructured":"NMR spectroscopic data of (SIdippH)Br are as follows:1H\u2005NMR (300.1\u2005MHz [D6]DMSO 298\u2005K ppm):\u03b4=1.19 (d 3J(H H)=6.8\u2005Hz 12\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 1.35 (d 3J(H H)=6.8\u2005Hz 12\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 3.09 (sept 3J(H H)=6.8\u2005Hz 4\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 4.56 (s 4\u2009H; 2\u00d7NCH2) 7.42 (d 3J(H H)=7.7\u2005Hz 4\u2009H; 2\u00d7C3 \u20095\u2010H dipp) 7.55 (t 3J(H H)=7.7\u2005Hz 2\u2009H; 2\u00d7C4\u2010H dipp) 9.49 (s 1\u2009H; NCHN).13C{1H} NMR (75.47\u2005MHz [D6]DMSO 298\u2005K ppm):\u03b4=23.3 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 24.9 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 28.2 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 53.7 (s 2\u2009C; 2\u00d7NCH2) 124.8* (s 4\u2009C; 2\u00d7C3 \u20095\u2010H dipp) 129.8* (s 2\u2009C; 2\u00d7C1 dipp) 131.0* (s 2\u2009C; 2\u00d7C4\u2010H dipp) 146.1* (s 4\u2009C; 2\u00d7C2 \u20096 dipp) 160.0\u2005ppm (s 1\u2009C; NCHN). The signals marked with an asterisk were either not or incorrectly assigned in reference [28]."},{"key":"e_1_2_5_78_2","doi-asserted-by":"publisher","DOI":"10.1055\/s-1993-25902"},{"key":"e_1_2_5_79_2","unstructured":"\u00a0"},{"key":"e_1_2_5_80_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-328X(00)80518-5"},{"key":"e_1_2_5_81_2","doi-asserted-by":"publisher","DOI":"10.1021\/om00018a041"},{"key":"e_1_2_5_82_2","unstructured":"\u00a0"},{"key":"e_1_2_5_83_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-1902(56)80073-0"},{"key":"e_1_2_5_84_2","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1002\/9780470132388.ch38","volume":"7","author":"Fischer E. O.","year":"1963","journal-title":"Inorg. Synth."},{"key":"e_1_2_5_85_2","unstructured":"Li[CpCr(CO)3]:1H\u2005NMR (400.1\u2005MHz CD3CN 298\u2005K):\u03b4=4.41\u2005ppm (s 5\u2009H; C5H5); IR (THF): 1902 (s) 1804 (vs) 1779 (m) 1717\u2005cm\u22121(s) (\u03bd(CO))."},{"key":"e_1_2_5_86_2","unstructured":"1H\u2005NMR spectroscopy revealed that compound1\u2010Brdecomposes slowly in CD2Cl2. Therefore the13C{1H}\u2005NMR spectrum of1\u2010Bralso displayed the signals of the decomposition products which could be easily distinguished from those of1\u2010Brdue to their lower intensity and by using correlation spectroscopy."},{"key":"e_1_2_5_87_2","unstructured":"The reaction of2\u2010Brwith Li[CpCr(CO)3] was carried out several times. In all cases addition of a fresh portion of Li[CpCr(CO)3] and repeated heating was necessary to complete the conversion of2\u2010Brdespite the presence of an excess amount of Li[CpCr(CO)3] during the first heating. This observation can be explained by the concomitant formation of (SIdippH)[CpCr(CO)3] which was found by NMR spectroscopy to be the major byproduct of this reaction. In addition lithium bromide precipitates out during the reaction which may cover the surface of Li[CpCr(CO)3] and decrease its activity. (SIdippH)[CpCr(CO)3] could be easily separated from3\u2010Brby taking advantage of its low solubility in toluene\/hexane (1:1) mixtures and isolated as a pale\u2010brown solid which was characterized by IR and NMR spectroscopy. IR and NMR spectroscopic data of (SIdippH)[CpCr(CO)3] are as follows:1H\u2005NMR (300.1\u2005MHz [D8]THF 298\u2005K):\u03b4=1.24 (d 3J(H H)=6.5\u2005Hz 12\u2009H; 4\u00d7CHMeAMeB) 1.42 (d 3J(H H)=6.5\u2005Hz 12\u2009H; 4\u00d7CHMeAMeB) 3.19 (br\u2009sept 4\u2009H; 4\u00d7CHMeAMeB) 4.29 (s 5\u2009H; C5H5) 4.73 (br\u2009s 4\u2009H; 2\u00d7NCH2) 7.38 (d 3J(H H)=7.7\u2005Hz 4\u2009H; 2\u00d7C3 \u20095\u2010H Dipp) 7.51\u2005ppm (t 3J(H H)=7.7\u2005Hz 2\u2009H; 2\u00d7C4\u2010H Dipp);13C{1H}\u2005NMR (75.47\u2005MHz [D8]THF 298\u2005K):\u03b4=24.1 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 25.5 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 29.7 (s 4\u2009C; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 55.6 (s 2\u2009C; 2\u00d7NCH2) 82.1 (s 5\u2009C;C5H5) 125.7 (s 4\u2009C; 2\u00d7C3 \u20095\u2010H Dipp) 130.9 (s 2\u2009C; 2\u00d7C1 dipp) 132.1 (s 2\u2009C; 2\u00d7C4\u2010H dipp) 147.7 (s 4\u2009C; 2\u00d7C2 \u20096 dipp) 161.0 (s 1\u2009C; NCHN) 246.9\u2005ppm (s 3\u2009C; 3\u00d7CO); IR (THF):$\\tilde \\nu $=1892 (vs) 1782 (vs) 1759\u2005cm\u22121(vs) [\u03bd(CO)]; IR (toluene):$\\tilde \\nu $=1887 (vs) 1778 (vs) 1753\u2005cm\u22121(vs) (\u03bd(CO))."},{"key":"e_1_2_5_88_2","unstructured":"[SiCl2(SIdipp)] (2\u2010Cl) was generated upon treatment of SiHCl3with two equivalents of SIdipp in toluene at \u221260\u2009\u00b0C and isolated after filtration of (SIdippH)Cl and evaporation of the solvent at ambient temperature as a yellow solid which was found by NMR spectroscopy to contain some impurities. Attempts to purify2\u2010Clby crystallization were not successful so far due to the low stability of2\u2010Clin solution and so the crude product was used for the synthesis of3\u2010Cl.1H\u2005NMR (300.1\u2005MHz C6D6 298\u2005K):\u03b4=1.12 (d 3J(H H)=6.7\u2005Hz 12\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 1.50 (d 3J(H H)=6.8\u2005Hz 12\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 3.25 (sept 3J(H H)=6.8\u2005Hz 4\u2009H; 2\u00d7C2 \u20096\u2010CHMeAMeB dipp) 3.42 (s 4\u2009H; 2\u00d7NCH2) 7.04 (d 3J(H H)=7.7\u2005Hz 4\u2009H; 2\u00d7C3 \u20095\u2010H dipp) 7.17\u2005ppm (t 3J(H H)=7.7\u2005Hz 2\u2009H; 2\u00d7C4\u2010H dipp)."},{"key":"e_1_2_5_89_2","unstructured":"SADABS 2009\/2 Bruker AXS 2009."},{"key":"e_1_2_5_90_2","unstructured":"G.\u2005M. Sheldrick SHELXS97 and SHELXL97 University of G\u00f6ttingen Germany 1997."},{"key":"e_1_2_5_91_2","unstructured":"CELL\u2002NOW 2009\/2 Bruker AXS 2009."},{"key":"e_1_2_5_92_2","unstructured":"SAINT 2009\/2 Bruker AXS 2009."},{"key":"e_1_2_5_93_2","unstructured":"TWINABS 2009\/2 Bruker AXS 2009."},{"key":"e_1_2_5_94_2","unstructured":"\u00a0"},{"key":"e_1_2_5_95_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.464913"},{"key":"e_1_2_5_96_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevB.37.785"},{"key":"e_1_2_5_97_2","doi-asserted-by":"publisher","DOI":"10.1063\/1.467146"},{"key":"e_1_2_5_98_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00533485"},{"key":"e_1_2_5_99_2","unstructured":"M.\u2005J. Frisch G.\u2005W. Trucks H.\u2005B. Schlegel G.\u2005E. Scuseria M.\u2005A. Robb J.\u2005R. Cheeseman J.\u2005A. Montgomery \u2005Jr. T. Vreven K.\u2005N. Kudin J.\u2005C. Burant J.\u2005M. Millam S.\u2005S. Iyengar J. Tomasi V. Barone B. Mennucci M. Cossi G. Scalmani N. Rega G.\u2005A. Petersson H. Nakatsuji M. Hada M. Ehara K. Toyota R. Fukuda J. Hasegawa M. Ishida T. Nakajima Y. Honda O. Kitao H. Nakai M. Klene X. Li J.\u2005E. Knox H.\u2005P. Hratchian J.\u2005B. Cross C. Adamo J. Jaramillo R. Gomperts R.\u2005E. Stratmann O. Yazyev A.\u2005J. Austin R. Cammi C. Pomelli J.\u2005W. Ochterski P.\u2005Y. Ayala K. Morokuma G.\u2005A. Voth P. Salvador J.\u2005J. Dannenberg V.\u2005G. Zakrzewski S. Dapprich A.\u2005D. Daniels M.\u2005C. Strain O. Farkas D.\u2005K. Malick A.\u2005D. Rabuck K. Raghavachari J.\u2005B. Foresman J.\u2005V. Ortiz Q. Cui A.\u2005G. Baboul S. Clifford J. Cioslowski B.\u2005B. Stefanov G. Liu A. Liashenko P. Piskorz I. Komaromi R.\u2005L. Martin D.\u2005J. Fox T. Keith M.\u2005A. Al\u2010Laham C.\u2005Y. Peng A. Nanayakkara M. Challacombe P.\u2005M.\u2005W. Gill B. Johnson W. Chen M.\u2005W. Wong C. Gonzalez and J.\u2005A. Pople GAUSSIAN 03 Revision B.05 Gaussian Inc. Pittsburgh PA 2003."},{"key":"e_1_2_5_100_2","unstructured":"NBO 5.0 Program \u2005E.\u2005D. Glendening J.\u2005K. Badenhoop A.\u2005E. Reed J.\u2005E. Carpenter J.\u2005A. Bohmann C.\u2005M. Morales F. Weinhold Theoretical Chemistry Institute University of Wisconsin Madison 2001."},{"key":"e_1_2_5_101_2","unstructured":"J.\u2005B. Foresman \u00c6. Frisch Exploring Chemistry with Electronic Structure Methods 2nd ed. Gaussian Inc. Pittsburg PA 1996."}],"container-title":["Chemistry \u2013 A European Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fchem.201102659","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/chem.201102659","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T18:46:35Z","timestamp":1760294795000},"score":1,"resource":{"primary":{"URL":"https:\/\/chemistry-europe.onlinelibrary.wiley.com\/doi\/10.1002\/chem.201102659"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,10,31]]},"references-count":106,"journal-issue":{"issue":"48","published-print":{"date-parts":[[2011,11,25]]}},"alternative-id":["10.1002\/chem.201102659"],"URL":"https:\/\/doi.org\/10.1002\/chem.201102659","archive":["Portico"],"relation":{},"ISSN":["0947-6539","1521-3765"],"issn-type":[{"value":"0947-6539","type":"print"},{"value":"1521-3765","type":"electronic"}],"subject":[],"published":{"date-parts":[[2011,10,31]]}}}