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Some binuclear complexes of iron and cobalt with isocyanide ligands
Journal of Organomerallic Chemisny, 47 (1973) C33-C35 0 EkevierSequoia S.A., Iausanne - Printedin The Netherlands
c33
PreLiminary communication time biuuclear complexes of iron and cobalt with isocyanide ligands
PrLJ.BOYLAN, J. BELLERBY, JOSEPHINE NEWMAN and A.R MANNING* Department
of Chemistry,
University
College, Betfield,
Dubtin 4 (Ireland)
(Received November 3x4 1972)
SUMMARY
Whereas Cos(CO)s and RNC (R = Me, Et, and Cy) react to give mixtures of [(RNC)s Co] (COG ] and the covalent, carbonyl-bridged [(RNC&$O~(CO)~_~] derivatives (m = I-3), [(z-dienyl)Fe(CO)s] 2 give only [(lr-dienyI)aFe2(CO)4_,(CNR),] complexes (dienyl = C5H5, Me&H4 and C9H7 ; n = 1-2) that exist in solution as mixtures of cis- and trans-CO- and RNC-bridged tautomers with the J,&NC species decreasing in importance as the bulk of R increases.
We have reinvestigated the reaction of Coz(CO)s with isocyanides, and have found that at room temperature a series of [(RNC),Coa (CO)s_m] complexes are formed as well as the previously reported [(RNQ5Co] [COB] salts”* (R = Me, Et, and Cy; m = l-3). The covalent compounds contain terminal CO, bridging CO, and terminal RNC ligands (Table 1). COALS gives a range of similar complexes as well as others which we have not identified, but with [(PhsP)Co(CO),] *, only [(I’hsP)2Co(CNR)a] [Co(CO),] salts were obtained. Isocyanides will replace one 3--5 , or two CO ligands of [(n-dienyl)Fe(CO)z] z compounds. In sohrtion, the [(lr-dienylb Fez (CO),_n(CNR)n] derivatives (dienyl = Cs Hs , Me& H4, or C9H7 ; n = 1 or 2) exist as mixtures of tautomers in equilibria which depend on the solvent, temperature, and R (Table I). Increasing the bulk of R brings about a decrease in the importance of those isomers of the monosubstituted complexes v&i&r have a bridging RNC group as these would be destabilized by the increasing steric interaction of R with a (X-C, HS)Fe(CO) moiety. When the isocyanide is terminally coordinated, such an interaction is not possible. A similar effect appears to operate when r. = 2. In the case of [(n-Cr,Hs)2F~(CO)s(CNBz)], it is probably the electronic
1835(10) [email protected]) 1810(10)
1842t9.3) 1830(10) 181719.8)
1876(0.7) 1863(0.5)
1996(8,3) 1982(9.3) 1967(10)
2064(7.0) 2041(6.2) 1997(13.6) 2122(7.7) ’ 1999(37.4)d 1999(11,3)d 1998(7#2) d 1997(4,3) d 19960.7) d
2067(7.0)
2156(4.2,br) ’ 2143c8.3,Ix)’ 2018G.8) 2129(12.0,br) ’ 21S3(10)’ 2179(5.6)c 1720(12,0)d 2119&l, br) c 1803(19.5)d 177200) 1737(5.9)d 2134c2.7,br) c 1774(10) 1802(4.7)d 2127t2.7,br) c 1741(2.0)d 1773(10) 1799(3J)d 2122(1.9,br) c 1731(1.4)d 1775(10) 1798(2.1)’ 2112U.6, br) c 1740(0”5)d 1772(10) 1801(1.0)d 2072(1.0)’ 2108(1.7,br) c 1796(sh) 1771(10) 1990(29#0)e 2127(4.4,br) Gd 1784(10)d 1720(21.4)dtE 1987c4.7)’ 1697UO.l) dtc 1783(10)d 2111 (5.2, br) ‘Jd .a Peakpositions(cm”’ ) with relativepeakheightsin parentheses. 6 Cy = cyclohexyl,i-BU= isobutyl,t-Be= tert-butyland BZ=:ban+ ’ Due to terminalu(CN)vibrations; br = broad,d Due solelyor in past to speciescontainingone bridgingisocyanidcl&and.e Due solelyor in partto speciescontainingtwo bridgingisocyanideligands,
(CO), (CYNC),Co, (CO), (CYNC),C~,(CQ, [(CyNC),Co) bCCO,,~ (n--C,H, ), Fe, (CO), (CNBz) (n-C,H,),~e:e,(CO),(CNMc) (PC,H,),FC~ (CO), (CNEt) (n-C,H,),‘I;e,(CO),(CNBu-i) (n-CsH,),~ee,(CO),(CNCy) (~C,H,),Fe~e,(CO),(CNBu-t) (n-C,H,),Pe,(CO),(CNMc), (~-C,H,),I~~,(CO),(CNCY),
(CyNC)Co,
2014(14.7) 2028(31.0) 2002(16.8) 2012(23.0) 1975(1017) 1991(11.5) 1889t8.0) 1953(33.2) 1953(14.8) 1953(11.3) 1953t8.7) 1952t6.3) 1952l6.8) 1944(15.3) 1953(13.2)’ 1941(13.4) 1951(7.1)e
Absotption bands a
INFRAREDSPECTRAOF SOMECOBALTAND IRONCOMPLEXES WITHISOCYANIDELICANDSINHEXANESOLUTION
TABLE1
c) g
PRELIMINARY COMMUNICATION
c35
effects of the benzyl group which cause the cl-RNC species to be so important. The shapes of the absorption bands due to the terminal and bridging v(W) vibrations of the monosubstituted complexes are consistent with cis and trans forms of both the terminal and bridged isocyanide species. In the spectrum of [(nCs H5 &,F+ (CO), (CNESu-t)], the terminal z&N) absorption band may be resolved into its two components. REFERENCES 1 2 3 4 5
A. Sacco, Gqzz. Chim. ItaL, 83 (1953) 632. -W.Hieber and J. SedImeier,Cfzem.Ber., 87 (1954) 789. Y. Yamamoto and N. Hagiiwa, Mem. Inst. Sci and Ind. Res. Osaka Univ., 27 (1970) 109 P.M. Treichel, J.J. Benedict, RW. Hess and J.P. Stenson, Chem Commun. (1970) 162?. W.J. Jet3 and RJ. Angelici,J. OrganometaL Chem, 35 (19’72) C37.
c33
PreLiminary communication time biuuclear complexes of iron and cobalt with isocyanide ligands
PrLJ.BOYLAN, J. BELLERBY, JOSEPHINE NEWMAN and A.R MANNING* Department
of Chemistry,
University
College, Betfield,
Dubtin 4 (Ireland)
(Received November 3x4 1972)
SUMMARY
Whereas Cos(CO)s and RNC (R = Me, Et, and Cy) react to give mixtures of [(RNC)s Co] (COG ] and the covalent, carbonyl-bridged [(RNC&$O~(CO)~_~] derivatives (m = I-3), [(z-dienyl)Fe(CO)s] 2 give only [(lr-dienyI)aFe2(CO)4_,(CNR),] complexes (dienyl = C5H5, Me&H4 and C9H7 ; n = 1-2) that exist in solution as mixtures of cis- and trans-CO- and RNC-bridged tautomers with the J,&NC species decreasing in importance as the bulk of R increases.
We have reinvestigated the reaction of Coz(CO)s with isocyanides, and have found that at room temperature a series of [(RNC),Coa (CO)s_m] complexes are formed as well as the previously reported [(RNQ5Co] [COB] salts”* (R = Me, Et, and Cy; m = l-3). The covalent compounds contain terminal CO, bridging CO, and terminal RNC ligands (Table 1). COALS gives a range of similar complexes as well as others which we have not identified, but with [(PhsP)Co(CO),] *, only [(I’hsP)2Co(CNR)a] [Co(CO),] salts were obtained. Isocyanides will replace one 3--5 , or two CO ligands of [(n-dienyl)Fe(CO)z] z compounds. In sohrtion, the [(lr-dienylb Fez (CO),_n(CNR)n] derivatives (dienyl = Cs Hs , Me& H4, or C9H7 ; n = 1 or 2) exist as mixtures of tautomers in equilibria which depend on the solvent, temperature, and R (Table I). Increasing the bulk of R brings about a decrease in the importance of those isomers of the monosubstituted complexes v&i&r have a bridging RNC group as these would be destabilized by the increasing steric interaction of R with a (X-C, HS)Fe(CO) moiety. When the isocyanide is terminally coordinated, such an interaction is not possible. A similar effect appears to operate when r. = 2. In the case of [(n-Cr,Hs)2F~(CO)s(CNBz)], it is probably the electronic
1835(10) [email protected]) 1810(10)
1842t9.3) 1830(10) 181719.8)
1876(0.7) 1863(0.5)
1996(8,3) 1982(9.3) 1967(10)
2064(7.0) 2041(6.2) 1997(13.6) 2122(7.7) ’ 1999(37.4)d 1999(11,3)d 1998(7#2) d 1997(4,3) d 19960.7) d
2067(7.0)
2156(4.2,br) ’ 2143c8.3,Ix)’ 2018G.8) 2129(12.0,br) ’ 21S3(10)’ 2179(5.6)c 1720(12,0)d 2119&l, br) c 1803(19.5)d 177200) 1737(5.9)d 2134c2.7,br) c 1774(10) 1802(4.7)d 2127t2.7,br) c 1741(2.0)d 1773(10) 1799(3J)d 2122(1.9,br) c 1731(1.4)d 1775(10) 1798(2.1)’ 2112U.6, br) c 1740(0”5)d 1772(10) 1801(1.0)d 2072(1.0)’ 2108(1.7,br) c 1796(sh) 1771(10) 1990(29#0)e 2127(4.4,br) Gd 1784(10)d 1720(21.4)dtE 1987c4.7)’ 1697UO.l) dtc 1783(10)d 2111 (5.2, br) ‘Jd .a Peakpositions(cm”’ ) with relativepeakheightsin parentheses. 6 Cy = cyclohexyl,i-BU= isobutyl,t-Be= tert-butyland BZ=:ban+ ’ Due to terminalu(CN)vibrations; br = broad,d Due solelyor in past to speciescontainingone bridgingisocyanidcl&and.e Due solelyor in partto speciescontainingtwo bridgingisocyanideligands,
(CO), (CYNC),Co, (CO), (CYNC),C~,(CQ, [(CyNC),Co) bCCO,,~ (n--C,H, ), Fe, (CO), (CNBz) (n-C,H,),~e:e,(CO),(CNMc) (PC,H,),FC~ (CO), (CNEt) (n-C,H,),‘I;e,(CO),(CNBu-i) (n-CsH,),~ee,(CO),(CNCy) (~C,H,),Fe~e,(CO),(CNBu-t) (n-C,H,),Pe,(CO),(CNMc), (~-C,H,),I~~,(CO),(CNCY),
(CyNC)Co,
2014(14.7) 2028(31.0) 2002(16.8) 2012(23.0) 1975(1017) 1991(11.5) 1889t8.0) 1953(33.2) 1953(14.8) 1953(11.3) 1953t8.7) 1952t6.3) 1952l6.8) 1944(15.3) 1953(13.2)’ 1941(13.4) 1951(7.1)e
Absotption bands a
INFRAREDSPECTRAOF SOMECOBALTAND IRONCOMPLEXES WITHISOCYANIDELICANDSINHEXANESOLUTION
TABLE1
c) g
PRELIMINARY COMMUNICATION
c35
effects of the benzyl group which cause the cl-RNC species to be so important. The shapes of the absorption bands due to the terminal and bridging v(W) vibrations of the monosubstituted complexes are consistent with cis and trans forms of both the terminal and bridged isocyanide species. In the spectrum of [(nCs H5 &,F+ (CO), (CNESu-t)], the terminal z&N) absorption band may be resolved into its two components. REFERENCES 1 2 3 4 5
A. Sacco, Gqzz. Chim. ItaL, 83 (1953) 632. -W.Hieber and J. SedImeier,Cfzem.Ber., 87 (1954) 789. Y. Yamamoto and N. Hagiiwa, Mem. Inst. Sci and Ind. Res. Osaka Univ., 27 (1970) 109 P.M. Treichel, J.J. Benedict, RW. Hess and J.P. Stenson, Chem Commun. (1970) 162?. W.J. Jet3 and RJ. Angelici,J. OrganometaL Chem, 35 (19’72) C37.