Dinitrogen bridged complexes

Table 4 Di- and Tri-nucleai Dinitrogen-bridged Complexes of Rhenium(I) with Transition Metals... 

RuCl(Tp)(L)] reacts with NaPF yielding the enantiomeri-cally and diastereomerically pure dinitrogen-bridged complexes... 

Dinitrogen-bridged complexes of /rani-ReCl(N2)(PMe2ph)4 with NbClj and TaCl, (1 1 adducts) and ZrCl, (2 1 adduct like TiC ) have been isolated. The N NMR spectra of these and other complexes of this type as well as dinitrogen complexes of rhenium(I) with the main group acceptor A1Mc3 have been studied. Fenske-Hall MO calculations have been carried out on the molecule [ MoQ4(OH) (/i-N2) ReCl(PH3)4 ]. ... 

Studt P, MacKay BA, Johnson SA, Patrick BO, Fryzuk MD, Tuczek F. Lewis adducts of the side-on end-on dinitrogen-bridged complex [ (NPN)Ta 2( X-H)2( X-ll ll -N2)] with AlMe3, GaMe3, and B(CsF5)3 synthesis, structure, and spectroscopic properties. Chem EurJ. 2005 11 604-618. 

Bis(cyclopentadienyl)zirconium(III) complexes alkynyl-bridged complexes, 4, 749 dinitrogen complexes, 4, 747 electrochemical reduction, 4, 745 phosphido-bridged complexes, 4, 750 Bis(cyclopentadienyl)zirconium(IV) complexes electrochemical reduction, 4, 745 with M-C r/)-bonds, 4, 895 with M-C r/i2-bonds, 4, 887 with M-C r/i3-bonds, 4, 884 with M-H bonds, 4, 878 with M-N bonds, 4, 910 with M-0 bonds, 4, 917 with M-P bonds, 4, 927 with M-S bonds, 4, 930 with M-Si bonds, 4, 925 non-functionalized metallocene halides, 4, 870 ring-functionalized metallocene halides, 4, 874 Bis(cyclopentadienyl)zirconium(III) halides, in organic synthesis, 4, 754... 

There has been a report of bridged dinitrogen complexes of iron(III) and chromium(lll) complexes, formed by reaction of the metallo(IlI)porphyrinate triftate with [Re(N2)(PMe2Ph)4Cl] to make the Fe-N-N-Re or Cr-N-N-Re bridged complexes. The Fe complex has a magnetic moment of about 4.4 /u-b at room temperature, consistent with a S = 312,512 admixed spin state for the iron(lll), and a pyrrole-H shift of -3.23 ppm, consistent with the expected weak-fteld nature of the N2 ligand. The stracture shows a linear Fe-N-N-Re unit (Fe-Nl-N2 = 170°, Nl-N2-Re = 177°) with Fe-N bond length of 1.93 similar to that of the TPPFe -azide complex (1.953 A). 

No detailed mechanistic study of these reactions has been made, and there is little evidence to support the intermediacy of nitrosyl or dinitrogen oxide complexes. Since this report, much interest has been shown in the efficient synthesis of oxide-bridged clusters and dimers of IIIA-VIA metals using nitrogen oxides as the oxidizing agents. The following reactions provide t5q)ical examples (205 207) ... 

The unexpectedly strong nucleophilicity of dinitrogen shown by its displacement of water in Eq. 15.42 is also exhibited in the formation of a bridged complex ... 

Treatment of (108) (R IV) with the dinitrogen compound Na[(N2)Mo(NButAr)3] provided the binuclear N2-bridged complex (110) (Scheme 20).193 Reduction of the latter produced the anion [L3NbN] (111) whose reaction with I2 in tol yielded a mixture of products frotn which cyclic [(L2Nb(/r2-N)]3 (112) was isolated. The latter contained both short (1.791(7)A) and long (2.004(6)A) Nb—N bonds.193... 

---