A Neutral η⁵‐Aminoborole Complex of Germanium(II)

Abstract

The synthesis of two η -aminoborole complexes of germanium(II) from the reaction of a germole dianion with aminoboron dichlorides is reported. This reaction constitutes a remarkable example of a germole-to-borole transformation. The two aminoborole complexes of germanium(II) were fully characterized by multinuclear NMR spectroscopy, IR spectroscopy, HRMS, and, in one case, by X-ray crystallography. The results of quantum-mechanical calculations favor the electronic structure of a half-sandwich complex of Ge over an ionic representation with a germanium dication stabilized by an aromatic aminoborole dianion.

Electronic Push–Pull Modulation by Peripheral Substituents in Pentaaryl Boroles

“…Aminoboroles have mainly been investigated regarding their d‐block coordination chemistry . Recently a p‐block complex of an aminoborole has been reported . To form dianionic precursors for coordination chemistry, usually amino‐3‐borolenes are deprotonated with no need to isolate the free aminoborole .…”

“…[82][83][84][85][86] Recently ap -blockc omplex of an aminoborole has been reported. [87] To form dianionic precursors for coordination chemistry,u sually amino-3-borolenes are deprotonated with no need to isolate the free aminoborole. [83] Therefore, despite their establishmenti nc oordination chemistry,o nly few derivatives of isolated free aminoboroles (apart from af ew amino derivativeso f9 -borafluorenes) [60,88] are known (Scheme 6, B-F).…”

Crystalline Boragermenes

“…Recently, Müller, Albers, and co‐workers synthesized an aminoborole complex of germanium(II) by reacting a germole dianion with aminoboron dichlorides. In this study, an intermediate VI featuring a Ge=B bond was proposed and computationally supported . To the best of our knowledge, neither a base‐free boragermene nor a base adduct have been isolated thus far.…”

A Neutral “Aluminocene” Sandwich Complex: η1‐ versus η5‐Coordination Modes of a Pentaarylborole with ECp* (E=Al, Ga; Cp*=C5Me5)

“…Recently Müller, Albers,a nd co-workers reported aG e IIborole complex that resulted from ar earrangement during the reaction of ag ermole dianion with amidoborane dihalides. [10] Although only af ew comments are found in the literature, [9d, 11] al ikely reason for the scarcity of p-block complexes,i np articular, is that borolediide salts act as reducing agents rather than as al igand source in metathesis reactions with p-block halides.…”