Amine addition to coordinated nitriles in tungsten(II) alkyne complexes

Journal Article · Sat May 01 00:00:00 EDT 1993 · Organometallics; (United States)

DOI:https://doi.org/10.1021/om00029a037· OSTI ID:5989569

Feng, S G; White, P S; Templeton, J L ^[1]

---

1. Univ. of North Carolina, Chapel Hill (United States)

Reaction of [Tp[prime](CO)(PhC[triple bond]CR[double prime])W(N[triple bond]CR)]BF[sub 4]RB with NH[sub 2]R[prime] generates cationic amidine complexes of the type [Tp[prime](CO)(PhC[triple bond]CR[double prime])W(NH=C(R)NHR[prime])][BF[sub 4]] (R = Me, R[prime] = H, R[double prime] = Me (1), H (2); R = Me, R[double prime] = Me, R[double prime] = Ph (3), C(CH[sub 3])[sub 3] (4); R[double prime] = H, R[prime] = Ph, R = Me (5), Ph (6)). These reactions reflect net addition of H-NHR[prime] across the nitrile triple bond. NMR spectra and a single crystal X-ray structure of 2 indicate that the alkyne ligand remains as a four-electron donor. Crystals of 2 belong to the monoclinic space group P2[sub 1]/n, Z = 4, with unit cell dimensions of a = 12.919(3) A, b = 18.550(4) A, c = 15.989(4) A, and [beta] = 99.08(2)[degrees]. Refinement of 433 variables over 3974 reflections led to an R value of 3.4% with R[sub w] = 4.7%. Deprotonation of the [alpha]-nitrogen of [Tp[prime](CO)(PhC[triple bond]CH)W(NH=C(Ph)NHPh)][BF[sub 4]] (6) with ammonia results in the formation of a neutral azavinylidene alkyne complex, Tp[prime](CO)(PhC[triple bond]CH)W-N=C(Ph)NHPh (9). NMR spectra of 9 indicate that the alkyne ligand adopts a three-electron donor role. Reaction of [Tp[prime](CO)(PhC[triple bond]CH)W(N[triple bond]CR)][BF[sub 4]] with either gaseous or aqueous ammonia produces neutral metallocycle complexes of the type Tp[prime](CO)W=C(Ph)-C(H)=H-C-(R)=N (R = Me (7), Ph (8)). An X-ray structure of 8 indicates that the six-membered metal-ligand ring is planar. The two metal-ligand bond distances in the ring are surprisingly short (W=C(Ph), 2.08(1) A; W=N, 1.769(8) A). The large W-N-C angle of 146.1(7)[degrees] in the ring is compatible with the two-bond tungsten-carbon coupling of 22 Hz here, which characterizes nearly linear W-N-C linkages. 24 refs., 2 figs., 6 tabs.

• OSTI ID: 5989569
• Journal Information: Organometallics; (United States), Journal Name: Organometallics; (United States) Vol. 12:5; ISSN ORGND7; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
360602 -- Other Materials-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMINES
AMMONIA
CHEMICAL REACTIONS
COMPLEXES
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
LIGANDS
MAGNETIC RESONANCE
NITRILES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RESONANCE
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES