An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H2E'‑BH2-NMe3 (E' = P, As) with pnictogen-based nucleophiles MER1R2 (E = P, As; R1 = H, R2 = tBu; R1 = R2 = Ph; M = Na, K) allows for the isolation of the unsymmetrical products [Na(18‑crown-6)][H2E'‑BH2‑EHtBu] (3: E = E' = P; 4: E = E' = As; 5: E = As, E' = P) and [M(C)][H2E'‑BH2‑EPh2] (7: E = E' = P, M = Na, C = 18‑crown-6; 8: E = E' = As; M = K, C = [2.2.2]cryptand; 9: E = P, E' = As, M = Na, C = [2.2.2]cryptand; 10: E = As, E' = P, M = K, C = [2.2.2]cryptand). [Na(18‑crown-6)][H2As‑BH2‑tBuPH-BH3] (6) is only accessible by a different pathway, using tBuPH2, BH3•SMe2 and NaNH2 as starting materials. Additionally, the synthesis of symmetrical diphenyl-substituted compounds [M(18‑crown-6)][Ph2E‑BH2-EPh2] (11: E = P, M = Na; 12: E = As, M = K) is reported which can be regarded as isostructural inorganic, negatively charged analogs of dppm (1,1-bis(diphenylphosphino)methane) and dpam (1,1‑bis(diphenylarsino)methane). Furthermore, an elongation of the pnictogen boron backbone in compounds 3, 7 and 9' (similar compound to 9, stabilized however by 18‑crown-6), is attainable by reacting them with the pnictogenylboranes H2E'‑BH2‑NMe3 leading to corresponding five-membered chain-like compounds [Na(18‑crown-6)][H2E‑BH2-R1R2P-BH2-E'H2] (E = E' = P, R1 = H, R2 = tBu (13); E = E' = P, R1 = R2 = Ph (14); E = E' = As, R1 = R2 = Ph (15); E = P, E' = As, R1 = R2 = Ph (16)). Finally, the thermodynamics of the reaction pathways were evaluated by quantum chemical computations.