A 14-vertex bud-shaped [(Cp*Ti)₂B₁₂H₁₈] cluster

Area of Science:

• Organometallic Chemistry
• Boron Chemistry
• Coordination Chemistry

Background:

• Titanaboranes are organometallic compounds containing titanium and boron.
• Macropolyhedral clusters represent complex, fused boron cage structures.
• Understanding cluster fusion rules is key to predicting and synthesizing novel boron cage compounds.

Purpose of the Study:

• To synthesize and structurally characterize novel macropolyhedral titanaboranes.
• To investigate the structural motifs and bonding in these complex clusters.
• To explore the applicability of existing theoretical rules (Mingos, Jemmis) to these new structures.

Main Methods:

• Synthesis of titanaborane clusters via chemical reactions.
• Single-crystal X-ray diffraction for structural determination.
• Spectroscopic and analytical techniques for characterization.

Main Results:

• Synthesis and structural characterization of a 14-vertex titanaborane, [(Cp*Ti)2B12H18] (1).
• Synthesis and isolation of a 17-vertex titanaborane, [(Cp*Ti)2(B15H20)(µ-SH)] (2).
• Cluster 1 features fused arachno-subclusters with inter-subcluster B-B linkages, deviating from established fusion formalisms.

Conclusions:

• The discovery of unusual titanaborane structures expands the known diversity of boron clusters.
• Cluster 1's unique geometry and failure to follow established rules highlight limitations in current theoretical models.
• Further research is needed to refine theoretical frameworks for predicting complex boron cluster structures.