Experimental and Theoretical Observations of Aromaticity in Heterocyclic XAl3− (X=Si, Ge, Sn, Pb) Systems

TLDR: In this paper, a white solid was removed in vacuo, leaving a white, X-ray quality crystals (0.86 g, 87% yield) precipitated from solution, over 24 h.

Abstract: 1: [(Cp*2 ZrH3Li)3] (0.1 g, 0.27 mmol) was dissolved in THF (3 mL), PH2CH2CH2PH2 (1.0 g, 10.87 mmol) was added dropwise to the stirred, colorless solution which became green, then aquamarine, and finally blue, over a period of 30 min. The reaction was stirred for 72 h, until it became colorless. Solvent was removed in vacuo, leaving a white solid which was dissolved in hexane, filtered, and placed in a freezer (y35 8C). Colorless, X-ray quality crystals (0.86 g, 87% yield) precipitated from solution, over 24 h. 1H NMR (C6D6): dˆ 3.65 (dt, 2H, 1JP,Hˆ 330, 3JH,Hˆ 10 Hz), 2.43 (m, 2H), 1.87 (m, 2H), 1.14 (m, 2H), 0.74 (m, 2H); 13C{1H} NMR (C6D6): dˆ 38.36, 30.66; 31P NMR (C6D6): dˆy22.5 (P1: JP1,P1ˆy237, JP1,P0ˆy186, 2JP1,P0ˆ 20 Hz), y65.4 (P0: 1JP1,P1ˆy237, 1JP1,P0ˆy186, 2JP1,P0ˆ 20 Hz); elemental analysis (%) calcd for P4C4H10: C 26.39, H 5.54; found: C 26.18, H 5.42.