Synthese und Struktur von ortho‐Phenylenzink

Abstract

Dimer im Kristall, trimer in Lösung ist ortho‐Phenylenzink, das jetzt aus der analogen Quecksilberverbindung und Zink synthetisiert werden konnte. In Lösung liegt das im Bild gezeigte Gleichgewicht weit auf der rechten Seite. Das Dimer kristallisiert wahrscheinlich wegen günstigerer Packungseffekte.

Synthesis of 9‐Gallafluorenes via Group 12 Metal Biphenylenes

“…In 8b the C–Zn–C angles in the ten membered Zn 2 C 8 rings are wide [141.85(7)°]. They are wider than that in an ortho ‐phenylene zinc dimer [130.3(6)°] with a six membered Zn 2 C 4 ring, but comparable to those in (Me 3 CCH 2 ) 2 Zn(tmeda) [148.3(1)°][22c] and Ph 2 Zn(dme) [146.6(2)°]. [22b]…”

1,8-Naphthalenediylzinc

“…As zinc is a much stronger Lewis acid than mercury, it is probably coordinated by two molecules of THF per zinc atom as was experimentally observed for dimeric 1,2-phenylenezinc [12], This substitution pattern is expected to cause too much strain for the structure to remain planar; therefore, we assume that lb will adopt a structure with a chair-like folding of the central eight-membered ring similar to that found in the crystal structures of ld-f where Ε resides slightly above and below the planes of the naphthalene ring systems (Scheme 2). However, the balance between the different oligomers may be subtle as illustrated by the related case of 1,2-phenylenezinc which is strictly trimeric in solution, but it crystallizes as the dimer [12], The ensuing strain will be less severe in lb because in diorganozinc compounds in which the zinc atom is surrounded by two organic groups and two THF molecules, C-Zn-C bond angles usually are 140 -160°, and as a consequence, the distortion of the naphthalene moiety from planarity of lb is probably less pronounced.…”

“…Inspired by the successful preparation of 1,2-phenylenezinc by transmetalation of 1,2-phenylenemercury with metallic zinc [12], we envisaged the synthesis of 1 b in a similar fashion from 1,8naphthalenediylmercury (lc) [7] (Scheme 1). For this purpose, lc was reacted with metallic zinc in THF at room temperature.…”

SYNTHESIS OF 9, 10-DIMETALLATRIPTYCENES CONTAINING GROUP 15 ELEMENTS FROM ortho-PHENYLENEMAGNESIUM

“…In contrast, the reaction of 14 [6], which is the zinc analogue of 4, with AsCI 3 gave 7 in 49 % yield. However, our attempts were so far unsuccessful.…”

“…15 15 ' . orffto-Phenylenemagnesium (4) [13], orfho-phenylenezinc (14) [6], and the tri-Grignard reagents 6a,b [2b,c,14] were prepared according to literature. orffto-Phenylenemagnesium (4) [13], orfho-phenylenezinc (14) [6], and the tri-Grignard reagents 6a,b [2b,c,14] were prepared according to literature.…”