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=Bu-t; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H2E '-BH2-(EHBu)-Bu-t] (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-(BuPH)-Bu-t-BH3] (6) is only accessible by a different pathway, using (BuPH2)-Bu-t, 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 ' H-2] (E=E '=P, R1=H, R2=Bu-t (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.