Novel triplet germylenes in focus: normal vs. abnormal triplet exocyclic tetrazol-5-vinylidene germylenes at DFT.

Substituent effects on stability (assumed as the singlet and triplet energy gaps, ΔΕ) of novel 1,4-disubstituted-tetrazole-5-vinylidene germylenes (normal, 1) and their corresponding 1,3-disubstituted-tetrazole-5-vinylidene germylenes (abnormal, 2) are computed and compared, at B3LYP/6-311++G** and M06/6-311++G**, where R = H, CN, CF, F, SH, CH, OMe, and OH. Interestingly, every triplet vinylidene germylene shows more stability than its corresponding singlet. Also, every triplet abnormal isomer (2) emerges to be more stable than its corresponding normal (1).

Theoretical descriptions of novel triplet germylenes M-Ge-M-M (M = H, Li, Na, K; M = Be, Mg, Ca; M = H, F, Cl, Br).

In a quest to identify new ground-state triplet germylenes, the stabilities (singlet-triplet energy differences, ΔE) of 96 singlet (s) and triplet (t) M-Ge-M-M species were compared and contrasted at the B3LYP/6-311++G**, QCISD(T)/6-311++G**, and CCSD(T)/6-311++G** levels of theory (M = H, Li, Na, K; M = Be, Mg, Ca; M = H, F, Cl, Br). Interestingly, F-substituent triplet germylenes (M = F) appear to be more stable and linear than the corresponding Cl- or Br-substituent triplet germylenes (M = Cl or Br). Triplets with M = K (i.